Method of Manufacturing a Part of a MEMS System

ABSTRACT

A method of manufacturing part of a microelectromechanical system (MEMS) and such part manufactured by the method are provided. The method comprises preparing first and second base members; imparting liquid repellency for a liquid material to at least part of a bonding film non-formation region of the first base member to form a liquid repellent region thereon; supplying the liquid material onto the first base member to selectively form a liquid coating on a bonding film formation region of the first base member with the aid of the liquid repellency of the liquid repellent region; drying the liquid coating to obtain a bonding film on the bonding film formation region; and bonding the first and second base members together through the bonding film due to a bonding property developed in the vicinity of a surface of the bonding film by applying energy thereto to obtain the bonded body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority under 35U.S.C. §120 on, application Ser. No. 12/397,384 filed Mar. 4, 2009,which claims priority under 35 U.S.C. §119 on Japanese PatentApplication No. 2008-056855 filed on Mar. 6, 2008, each of which isexpressly incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to a method of manufacturing a part of amicroelectromechanical system (MEMS) that includes bonded body in whicha first base member and a second base member are partially bondedtogether through a bonding film and a bonded body manufactured usingsuch a method.

2. Related Art

Conventionally, when two members (base members) are bonded together toobtain a bonded body, a method, in which the two members are bondedtogether through an adhesive layer formed of an adhesive such as anepoxy-based adhesive or an urethane-based adhesive, has been often used.

In general, an adhesive exhibits reliably high adhesiveness regardlessof constituent materials of the members to be bonded. Therefore, membersformed of various materials can be bonded together in variouscombinations.

For example, a liquid droplet ejection head (an ink-jet type recordinghead) included in an ink-jet printer is assembled by bonding, using anadhesive, several members formed of different kinds of materials such asa resin-based material, a metal-based material, and a silicon-basedmaterial together.

When the members are to be bonded together using the adhesive to obtainan assembled body composed from the members, a liquid or paste adhesiveis applied to surfaces of the members, and then the members are attachedto each other via the applied adhesive on the surfaces thereof andfirmly fixed together by hardening (setting) the adhesive with an actionof heat or light.

However, in the case where the members are bonded together using theadhesive, there are problems in that (i) bonding strength between themembers is low, (ii) dimensional accuracy of the obtained assembled bodyis low (for example, the adhesive is squeezed out from the assembledbody), (iii) it takes a relatively long time until the adhesive ishardened, and (iv) the adhesive has low ink resistance (highresolvability against an organic solvent).

Further, it is often necessary to treat the surfaces of the members tobe bonded using a primer in order to improve the bonding strengthbetween the members. Therefore, additional cost and labor hour arerequired for performing the primer treatment, which causes an increasein cost and complexity of the process for bonding the members.

On the other hand, as a method of bonding members without using theadhesive, there is known a solid bonding method. The solid bondingmethod is a method of directly bonding members without an interventionof an intermediate layer composed of an adhesive or the like (see, forexample, JP-A-5-82404).

Since such a solid bonding method does not need to use the intermediatelayer composed of the adhesive or the like for bonding the members, itis possible to obtain a bonded body of the members having highdimensional accuracy.

However, the solid bonding method has the following problems: (A)constituent materials to be bonded are limited to specific kinds, (B) aheat treatment using a high temperature (e.g., about 700 to 800° C.)must be carried out in a bonding process, (C) an ambient atmosphere inthe bonding process is limited to a reduced atmosphere, (D) since it isdifficult to obtain a bonded body in which two members are partiallybonded together, large stress due to a difference between thermalexpansion coefficients of the two members is likely to be generated in abonding interface therebetween, resulting in separation of the membersof the bonded body.

In view of such problems, there is a demand for a method which iscapable of partially and firmly bonding members with high dimensionalaccuracy and efficiently bonding them together at a low temperatureregardless of constituent materials of the members to be bonded.

SUMMARY

Accordingly, it is an object of the present invention to provide amethod of manufacturing a part of a MEMS that includes bonded body bywhich two base members can be partially and firmly bonded together withhigh dimensional accuracy and can be efficiently bonded together at alow temperature, and a bonded body in which the two base members arepartially bonded together using such a method.

A first aspect of the present invention is directed to a method ofmanufacturing a part of a MEMS including a bonded body in which a firstbase member and a second base member are bonded together through abonding film formed using a liquid material containing a siliconematerial composed of silicone compounds.

The method comprises: preparing the first base member having a surface,a bonding film formation region, where the bonding film is to be formed,provided on the surface and a bonding film non-formation region, wherethe bonding film is not to be formed, provided on the surface so as tobe adjacent to the bonding film formation region, and the second basemember; imparting liquid repellency for the liquid material to at leasta part of the bonding film non-formation region to form a liquidrepellent region thereon; supplying the liquid material onto the firstbase member to selectively form a liquid coating on the bonding filmformation region with the aid of the liquid repellency of the liquidrepellent region; drying the liquid coating to obtain the bonding filmon the bonding film formation region; and bonding the first base memberand the second base member together through the bonding film due to abonding property developed in a vicinity of a surface of the bondingfilm by applying energy thereto to thereby obtain the bonded body.

This makes it possible to partially and firmly bond the first basemember and the second base member together with high dimensionalaccuracy, and to efficiently bond them together at a low temperature.

Further, in the bonded body, a gap having a size corresponding to athickness of the bonding film is formed between the first base memberand the second base member. Therefore, by suitably controlling the shapeof the bonding film, it is possible to form closed spaces, flow paths orthe like in the bonded body by utilizing the gap.

In the above method, it is preferred that each of the silicone compoundshas a polydimethylsiloxane chemical structure as a main chemicalstructure thereof.

Such silicone compounds can be preferably used as a major component ofthe silicone material, because they can be relatively easily availableat a low price, and methyl groups included in the polydimethylsiloxanechemical structure can be easily broken and removed therefrom byapplying the energy to the bonding film to thereby reliably develop thebonding property therein.

In the above method, it is preferred that each of the silicone compoundshas at least one silanol group.

In this case, when drying the liquid coating to transform it into thebonding film, hydroxyl groups (included in the silanol groups) of theadjacent silicone compounds are bonded together. Therefore, the thusformed bonding film can have more excellent film strength.

In the above method, it is preferred that the liquid repellent region isformed so as to surround the bonding film formation region.

In this case, the liquid material supplied onto the first base membercan reliably stay within the bonding film formation region to therebyform the liquid coating. This makes it possible to reliably form aliquid coating having a shape corresponding to that of the bonding filmformation region.

In the above method, it is preferred that the liquid repellent region isformed by introducing liquid repellent functional groups each having theliquid repellency for the liquid material to the bonding filmnon-formation region or by forming a liquid repellent film having theliquid repellency for the liquid material on the bonding filmnon-formation region.

This makes it possible to easily form the liquid repellent region on thebonding film non-formation region, even if it has a complex pattern(shape).

In the above method, it is preferred that each of the liquid repellentfunctional groups is a fluoroalkyl group.

In this case, the liquid repellent region can exhibit excellent liquidrepellency for the liquid material.

In the above method, it is preferred that the liquid repellent film is aself-assembled film or a plasma polymerization film.

This makes it possible to effectively obtain a dense and homogeneousliquid repellent film.

In the above method, it is preferred that in the liquid material supplystep, before the liquid material is supplied onto the first base member,the bonding film formation region is subjected to a liquid wettabletreatment capable of imparting liquid wettability for the liquidmaterial to the bonding film formation region.

In this case, when the liquid material is supplied onto the first basemember, it is repelled due to the liquid repellency of the liquidrepellent region while being gathered onto the bonding film formationregion due to the liquid wettability thereof. As a result, the liquidmaterial can be selectively and reliably supplied onto the bonding filmformation region.

In the above method, it is preferred that the liquid wettable treatmentis performed by introducing hydroxyl groups to the bonding filmformation region.

The hydroxyl groups can be easily introduced into the bonding filmformation region by subjecting the bonding film formation region to anoxidation treatment using a simple method such as a method in which itis heated or a method in which an ultraviolet ray is irradiated thereon.

In the above method, it is preferred that in the bonding step, after thefirst base member and the second base member are laminated togetherthrough the bonding film, the energy is applied to the bonding film tothereby bond them together through the bonding film.

In a sate that the first base member and the second base member arelaminated together, the bonding films are not bonded together.Therefore, since the first base member can be slid with respect to thesecond base member, it is possible to finely adjust a relative positiontherebetween with ease. As a result, dimensional accuracy of the finallyobtained bonded body can be further improved.

In the above method, it is preferred that in the bonding step, theenergy is applied to the bonding film by at least one method selectedfrom the group comprising a method in which an energy beam is irradiatedon the bonding film, a method in which the bonding film is heated and amethod in which a compressive force is applied to the bonding film.

This makes it possible to effectively activate the surface of thebonding film. Further, according to the above method, it is possible toprevent excessive breakage of molecular bonds of the silicone compoundscontained in the bonding film. Therefore, it is possible to prevent aproperty of the bonding film from being lowered.

In the above method, it is preferred that the energy beam is anultraviolet ray having a wavelength of 126 to 300 nm.

Use of the ultraviolet ray having such a wavelength makes it possible tooptimize an amount of the energy to be applied to the bonding film. As aresult, it is possible to prevent excessive breakage of the molecularbonds of the silicone compounds constituting a main portion (a trunkportion) of the bonding film, and to selectively break the molecularbonds of the silicone compounds present in the vicinity of the surfaceof the bonding film. This makes it possible for the bonding film todevelop the bonding property, while preventing a property thereof frombeing lowered.

In the above method, it is preferred that a temperature of the heatingis in the range of 25 to 100° C.

This makes it possible to reliably improve bonding strength between thefirst base member and the second base member while reliably preventingthem (the bonded body) from being thermally altered and deteriorated.

In the above method, it is preferred that the compressive force is inthe range of 0.2 to 10 MPa.

This makes it possible to reliably improve bonding strength between thefirst base member and the second base member, while preventingoccurrence of damages and the like therein due to an excess pressure.

In the above method, it is preferred that in the bonding step, theenergy is applied to the bonding film in an air atmosphere.

By doing so, it becomes unnecessary to spend a labor hour and a cost forcontrolling the ambient atmosphere. This makes it possible to easilyperform the application of the energy.

In the above method, it is preferred that an average thickness of thebonding film is in the range of 100 nm to 100 μm.

This makes it possible to prevent dimensional accuracy of the bondedbody obtained by bonding the first base member and the second basemember together from being significantly lowered, thereby enabling tomore firmly bond them together.

In the above method, it is preferred that at least a portion of thefirst base member which makes contact with the bonding film is composedof a silicon material, a metal material or a glass material as a majorcomponent thereof.

This makes it possible to improve bonding strength of the bonding filmto each of the first and second base members, even if each of them isnot subjected to a surface treatment.

In the above method, it is preferred that the second base member has abonding film which is the same as the bonding film formed on the firstbase member, and in the bonding step, the first base member and thesecond base member are bonded together through the bonding films.

This makes it possible to obtain a bonded body having higher bondingstrength between the first base member and the second base member.

It is preferred that the above bonding method further comprisessubjecting the bonded body to a treatment for improving bonding strengthbetween the first base member and the second base member after thebonding step.

This makes it possible to further improve the bonding strength betweenthe first base member and the second base member.

In the above method, it is preferred that the treatment for improvingthe bonding strength is performed by at least one method selected fromthe group comprising a method in which an energy beam is irradiated onthe bonding film and a method in which the bonding film is heated.

This makes it possible to further improve the bonding strength betweenthe first base member and the second base member easily.

A second aspect of the present invention is directed to a part of a MEMSmanufactured using the above method.

Such a bonded body can have high reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1E and 2F to 2H are sectional views for explaining a firstembodiment of a method of manufacturing a bonded body (a bonding method)according to the present invention.

FIGS. 3A to 3E, 4F and 4G are sectional views for explaining a secondembodiment of the method of manufacturing the bonded body according tothe present invention.

FIGS. 5A and 5B are sectional views for explaining a third embodiment ofthe method of manufacturing the bonded body according to the presentinvention.

FIG. 6 is an exploded perspective view showing an ink jet type recordinghead (a liquid droplet ejection head) in which the bonded body accordingto the present invention is used.

FIG. 7 is a section view illustrating a main portion of the ink jet typerecording head shown in FIG. 6.

FIG. 8 is a schematic view showing an embodiment of an ink jet printerequipped with the ink jet type recording head shown in FIG. 6.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a method of manufacturing a part of a MEMS including bondedbody and a bonded body according to the present invention will bedescribed in detail with reference to preferred embodiments shown in theaccompanying drawings.

The method of manufacturing the part of the MEMS of the presentinvention is a method by which two base members (a first base member 21and a second base member 22) are partially bonded together through abonding film 3, 3 a or 3 b.

The bonding film 3, 3 a or 3 b is a film formed of a silicone materialcomposed of silicone compounds as a major component thereof. Such abonding film 3, 3 a or 3 b can develop a bonding property in a region ofa surface thereof to which energy is applied.

By using the bonding film 3, 3 a or 3 b having such a property, it ispossible to firmly bond the two base members 21 and 22 together withhigh dimensional accuracy and efficiently bond them together at a lowtemperature. Further, according to the present invention, it is possibleto obtain a bonded body 1 having high reliability in which the two basemembers 21 and 22 are partially and firmly bonded together.

Method of Manufacturing Bonded Body

First Embodiment

First, description will be made on a first embodiment of the method ofmanufacturing the bonded body (a bonding method) of the presentinvention.

FIGS. 1A to 1E and 2F to 2H are sectional views for explaining the firstembodiment of the method of manufacturing the bonded body according tothe present invention. In this regard, it is to be noted that in thefollowing description, an upper side in each of FIGS. 1A to 1E and 2F to2H will be referred to as “upper” and a lower side thereof will bereferred to as “lower”.

The method of manufacturing the bonded body according to this embodimentcomprises: preparing the first base member 21 having a bonding filmformation region 41 where the bonding film is to be formed and a bondingfilm non-formation region 42 where the bonding film 3 is not to beformed, and the second base member (an adherend) 22; imparting liquidrepellency for a liquid material 30 for forming the bonding film 3 tothe bonding film non-formation region 42 to form a liquid repellentregion thereon; supplying the liquid material 30 containing the siliconematerial onto the first base member 21 to selectively form a liquidcoating 31 on the bonding film formation region 41; drying the liquidcoating 31 to obtain the bonding film 3 on the bonding film formationregion 41; applying energy to the bonding film 3 to develop the bondingproperty in a vicinity of a surface thereof; and laminating the firstbase member 21 and the second base member 22 (the adherend) together sothat the second base member 22 makes close contact with the bonding film3 to thereby obtain a bonded body 1 in which the base members 21 and 22are partially bonded together through the bonding film 3.

Hereinafter, the method of manufacturing the bonded body according tothis embodiment will be described one after another.

[1] First, the first base member 21 and the second base member 22 areprepared.

A constituent material of each of the first base member 21 and thesecond base member 22 is not particularly limited to a specific type.Examples of the constituent material of each of them include: aresin-based material such as polyolefin (e.g., polyethylene,polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetatecopolymer (EVA)), cyclic polyolefin, denatured polyolefin, polyvinylchloride, polyvinylidene chloride, polystyrene, polyamide, polyimide,polyamide-imide, polycarbonate, poly-(4-methylpentene-1), ionomer,acrylic resin, polymethyl methacrylate, acrylonitrile-butadiene-styrenecopolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin),butadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA),ethylene-vinyl alcohol copolymer (EVOH), polyester (e.g., polyethyleneterephthalate (PET), polyethylene naphthalate, polybutyleneterephthalate (PBT), polycyclohexane terephthalate (PCT)), polyether,polyether ketone (PEK), polyether ether ketone (PEEK), polyether imide,polyacetal (POM), polyphenylene oxide, denatured polyphenylene oxide,polysulfone, polyether sulfone, polyphenylene sulfide, polyarylate,aromatic polyester (e.g., liquid crystal polymer), fluoro resin (e.g.,polytetrafluoroethylene, polyfluorovinylidene), thermoplastic elastomer(e.g., styrene-based elastomer, polyolefin-based elastomer,polyvinylchloride-based elastomer, polyurethane-based elastomer,polyester-based elastomer, polyamide-based elastomer,polybutadiene-based elastomer, trans-polyisoprene-based elastomer,fluororubber-based elastomer, chlorinated polyethylene-based elastomer),epoxy resin, phenolic resin, urea resin, melamine resin, aramid resin,unsaturated polyester, silicone resin, polyurethane, or a copolymer, ablended body and a polymer alloy each having at least one of thesematerials as a major component thereof; a metal-based material such as ametal (e.g., Fe, Ni, Co, Cr, Mn, Zn, Pt, Au, Ag, Cu, Pd, Al, W, Ti, V,Mo, Nb, Zr, Pr, Nd, Sm), an alloy containing at least one of thesemetals, carbon steel, stainless steel, indium tin oxide (ITO) or galliumarsenide; a silicon-based material such as monocrystalline silicon,polycrystalline silicon or amorphous silicon; a glass-based materialsuch as silicic acid glass (quartz glass), silicic acid alkali glass,soda lime glass, potash lime glass, lead (alkaline) glass, barium glassor borosilicate glass; a ceramic-based material such as alumina,zirconia, ferrite, silicon nitride, aluminum nitride, boron nitride,titanium nitride, carbon silicon, boron carbide, titanium carbide ortungsten carbide; a carbon-based material such as graphite; a complexmaterial containing any one kind of the above materials or two or morekinds of the above materials; and the like.

Further, a surface of each of the first base member 21 and the secondbase member 22 may be subjected to a plating treatment such as a Niplating treatment, a passivation treatment such as a chromate treatment,a nitriding treatment, or the like.

The constituent material of the first base member 21 may be differentfrom or the same as that of the second base member 22.

It is preferred that the first base member 21 and the second base member22 have substantially equal thermal expansion coefficients with eachother. In the case where the first base member 21 and the second basemember 22 have the substantially equal thermal expansion coefficientswith each other, when the first base member 21 and the second basemember 22 are bonded together, stress due to thermal expansion is lesseasily generated on a bonding interface therebetween (that is, in thebonding film 3). As a result, it is possible to reliably preventoccurrence of peeling in the bonded body 1 finally obtained.

As described in detail below, even if the first base member 21 and thesecond base member 22 have the different thermal expansion coefficientswith each other, by optimizing conditions for bonding the first basemember 21 and the second base member 22 in the step which will bedescribed below, they can be firmly bond together with high dimensionalaccuracy.

Further, it is preferred that at least one of the two base members 21and 22 is composed of a resin material. The base member composed of theresin material can be easily deformed due to plasticity of the resinmaterial itself.

Therefore, it is possible to reduce stress which would be generated onthe bonding interface between the two base members 21 and 22 (e.g.,stress due to thermal expansion thereof) when they are bonded togetherthrough the bonding film 3.

As a result, breakage of the bonding interface becomes hard. This makesit possible to obtain a bonded body 1 having high bonding strengthbetween the two base members 21 and (including bonding strength betweenthe first base member 21 and the bonding film and bonding strengthbetween the second base member 22 and the bonding film 3).

From the above viewpoint, it is preferred that at least one of the twobase members 21 and 22 has flexibility. This makes it possible to obtaina bonded body 1 having improved bonding strength between the two basemembers 21 and 22.

In addition, in the case where the two base members 21 and 22 haveflexibility, it is possible to obtain a bonded body 1 having flexibilityas a whole thereof. Therefore, such a bonded body 1 can have highfunctionality.

Further, a shape of each of the base members 21 and may be a plate shape(a film shape), a massive shape (a blocky shape), a stick shape, or thelike, as long as it has a shape with a surface which can support thebonding film 3.

In this embodiment, as shown in FIG. 1A, each of the base members 21 and22 has the plate shape, a region other than a circumference region of anupper surface (a bonding surface 23) of the first base member 21 isdefined as the bonding film formation region 41 where the bonding film 3is to be formed.

Further, in the case where the base members 21 and 22 have the plateshape, respectively, they can be easily bent. Therefore, one of the basemembers 21 and 22 becomes sufficiently bendable (deformable) accordingto a shape of the other base member when they are laminated together.This makes it possible to improve the bonding strength between the basemembers 21 and 22 in the finally obtained bonded body 1.

In addition, since the base members 21 and 22 can be easily bent, stresswhich would be generated in the bonding interface therebetween can bereduced to some extent. In this case, an average thickness of each ofthe base members 21 and 22 is not particularly limited to a specificvalue, but is preferably in the range of about 0.01 to 10 mm, and morepreferably in the range of about 0.1 to 3 mm.

Next, the bonding surface 23 of the first base member is subjected to asurface treatment for improving bonding strength between the first basemember 21 and the bonding film 3, if needed.

By doing so, since the bonding surface 23 is cleaned and activated, thebonding film 3 can chemically affect the bonding surface 23 easily. As aresult, in the subsequent step, when the bonding film 3 is formed on thebonding surface 23, it is possible to improve the bonding strengthbetween the bonding film 3 and the first base member 21 (the bondingsurface 23).

Such a surface treatment is not particularly limited to a specific type.Examples of the surface treatment include: a physical surface treatmentsuch as a sputtering treatment or a blast treatment; a chemical surfacetreatment such as a plasma treatment performed using oxygen plasma andnitrogen plasma, a corona discharge treatment, an etching treatment, anelectron beam irradiation treatment, an ultraviolet ray irradiationtreatment or an ozone exposure treatment; a treatment performed bycombining two or more kinds of these surface treatments; and the like.

In this regard, it is to be noted that in the case where the first basemember 21 to be subjected to the surface treatment is formed of a resinmaterial (a polymeric material), the corona discharge treatment, thenitrogen plasma treatment and the like are particularly preferably used.

Especially, by carrying out the plasma treatment or the ultraviolet rayirradiation treatment as the surface treatment, it is possible to morereliably clean and activate the bonding surface 23. As a result, thebonding strength between the first base member 21 and the bonding film 3can be especially improved.

Depending on the constituent material of the first base member 21, thebonding strength of the bonding film 3 to the first base member 21becomes sufficiently high even if the bonding surface 23 of the firstbase member 21 is not subjected to the surface treatment describedabove.

Examples of the constituent material of the first base member 21 withwhich such an effect is obtained include materials containing variouskinds of the metal-based material, various kinds of the silicon-basedmaterial, various kinds of the glass-based material and the like as amajor component thereof.

The surface of the first base member 21 formed of such materials iscovered with an oxide film. In the oxide film, hydroxyl groups exist ina surface thereof. Therefore, by using the first base member 21 coveredwith such an oxide film, it is possible to improve the bonding strengthbetween the first base member 21 (the bonding surface 23) and thebonding film 3 without subjecting the bonding surface 23 to the surfacetreatment described above.

In this regard, it is to be noted that in this case, the entire of thefirst base member 21 may not be composed of the above materials, as longas a vicinity of the bonding surface 23 of the first base member 21 iscomposed of the above materials.

Further, instead of the surface treatment, an intermediate layer mayhave been, in advance, provided on the bonding surface 23 of the firstbase member 21. This intermediate layer may have any function.

Such a function is not particularly limited to a specific kind. Examplesof the function include: a function of improving the bonding strength ofthe first base member 21 to the bonding film 3; a cushion property (thatis, a buffering function); a function of reducing stress concentration;and the like. By forming the bonding film 3 on such an intermediatelayer, a bonded body 1 having high reliability can be obtained finally.

A constituent material of the intermediate layer include: a metal-basedmaterial such as aluminum or titanium; an oxide-based material such asmetal oxide or silicon oxide; a nitride-based material such as metalnitride or silicon nitride; a carbon-based material such as graphite ordiamond-like carbon; a self-organization film material such as a silanecoupling agent, a thiol-based compound, a metal alkoxide or a metalhalide; a resin-based material such as a resin-based adhesive agent, aresin filming material, a resin coating material, various rubbers orvarious elastomers; and the like, and one or more of which may be usedindependently or in combination.

Among intermediate layers composed of these various materials, use ofthe intermediate layer composed of the oxide-based material makes itpossible to further improve the bonding strength between the first basemember 21 and the bonding film 3 through the intermediate layer.

On the other hand, like the first base member 21, the bonding surface 24of the second base member 22 may have been, in advance, subjected to asurface treatment for improving bonding strength between the second basemember 22 (the bonding surface 24) and the bonding film 3, if needed. Bydoing so, the bonding surface 24 is cleaned and activated. As a result,it is possible to improve the bonding strength between the second basemember 22 and the bonding film 3.

Such a surface treatment is not particularly limited to a specific type,but the same surface treatment as the above mentioned surface treatment,to which the bonding surface 23 of the first base member 21 issubjected, can be used.

Further, like the first base member 21, depending on the constituentmaterial of the second base member 22, the bonding strength between thesecond base member 22 and the bonding film 3 becomes sufficiently higheven if the bonding surface 24 is not subjected to the above surfacetreatment.

Examples of the constituent material of the second base member 22 withwhich such an effect is obtained include the above mentioned materialscontaining the various kinds of the metal-based material, the variouskinds of the silicon-based material, the various kinds of theglass-based material and the like as the main material thereof.

The surface of the second base member 22 formed of such materials iscovered with an oxide film. In the oxide film, hydroxyl groups exist ina surface thereof. Therefore, by using such a second base member 22covered with the oxide film, it is possible to improve the bondingstrength between the second base member 22 (the bonding surface 24) andthe bonding film 3 without subjecting the bonding surface 24 to thesurface treatment described above.

In this regard, it is to be noted that in this case, the entire of thesecond base member 22 may not be composed of the above materials, aslong as at least a vicinity of the bonding surface 24 of the second basemember 22 is composed of the above materials.

Furthermore, if the bonding surface 24 of the second base member 22 hasthe following groups and substances, the bonding strength between thesecond base member 22 and the bonding film 3 can become sufficientlyhigh even if the bonding surface 24 is not subjected to the surfacetreatment described above.

Examples of such groups and substances include at least one group orsubstance selected from the group comprising various kinds of functionalgroups such as a hydroxyl group, a thiol group, a carboxyl group, anamino group, a nitro group and an imidazole group, various kinds ofradicals, leaving intermediate molecules such as an open circularmolecule and a molecule having at least one unsaturated (double ortriple) bond, halogen such as F, Cl, Br or I, and peroxides, anddangling bonds (or uncoupled bonds) generated by leaving the abovegroups from atoms to which they had been bonded (that is, dangling bondspresent in the atoms not terminated by leaving the above groupstherefrom).

Among the leaving intermediate molecules, hydrocarbon molecules eachincluding the open circular molecule or the unsaturated bond arepreferably selected. Such hydrocarbon molecules affect the bonding film3 based on marked reactivity thereof. Therefore, the second base member22 having such hydrocarbon molecules on the bonding surface 24 thereofcan be particularly firmly bonded to the bonding film 3.

Further, among the functional groups, the hydroxyl group is preferablyselected. In the case where the bonding surface 24 has a plurality ofthe hydroxyl groups, it becomes possible for the second base member 22to firmly bond to the bonding film 3 with ease.

By appropriately performing one selected from various surface treatmentdescribed above, the bonding surface 24 having such groups andsubstances can be obtained. This makes it possible to obtain a secondbase member 22 that can be firmly bonded to the bonding film 3.

Among them, it is preferred that the hydroxyl groups exist on thebonding surface 24 of the second base member 22. Such a bonding surface24 and the surface of the bonding film 3 exposing the hydroxyl groupsstrongly attract with each other to form hydrogen bonds between thehydroxyl groups. This makes it possible to particularly firmly bond thefirst base member 21 and the second base member 22.

Further, like the first base member 21, instead of the surfacetreatment, a surface layer may have been, in advance, provided on thebonding surface 24 of the second base member 22. This surface layer mayhave any function, like in the case of the first base member 21.

Such a function is not particularly limited to a specific kind. Examplesof the function include: a function of improving the bonding strength ofthe second base member 22 to the bonding film 3; a cushion property(that is, a buffering function); a function of reducing stressconcentration; and the like. By bonding the second base member 22 andthe bonding film through such a surface layer, a bonded body 1 havinghigh reliability can be obtained finally.

As for a constituent material of such a surface layer, for example, thesame material as the constituent material of the intermediate layerformed on the bonding surface 23 of the first base member 21 can beused.

In this regard, it is to be noted that the above mentioned surfacetreatment and formation of the intermediate may be carried out on thebonding film formation region 41, after the liquid repellent region 43is formed on a base member on which the liquid repellent region 43 is tobe formed (in this embodiment, the first base member 21) in thefollowing step [2].

Further, such a surface treatment and formation of the intermediateand/or surface layer may be carried out, if necessary. For example, inthe case where high bonding strength between the first base member 21and the second base member 22 is not required, the surface treatment andformation of the intermediate and/or surface layer can be omitted.

[2] Next, the liquid repellency for the liquid material 30 containingthe silicone material, which is to be supplied onto the bonding surface23 of the first base member 21 in the following step [3], is imparted tothe bonding film non-formation region 42 to thereby form the liquidrepellent region thereon. In this regard, the bonding film non-formationregion 42 is a region other than the bonding film formation region 41 ofthe bonding surface 23 and is provided so as to be adjacent to thebonding film formation region 41.

In this regard, in this specification, the term “the liquid repellencyfor the liquid material 30 containing the silicone material” means lowwettability for the liquid material 30 containing the silicone material.

Specifically, a contact angle of the liquid material 30 with respect tothe liquid repellent region 43 is preferably 90° or more, and morepreferably 110° or more. This makes it possible for the liquid repellentregion 43 to exhibit sufficient high liquid repellency for the liquidmaterial 30.

The liquid repellency can be imparted to the bonding film non-formationregion 42 using <I> a method in which liquid repellent functional groupseach having the liquid repellency for the liquid material 30 areintroduced to the above region 42, <II> a method in which, as shown inFIG. 1B, a liquid repellent film 431 having the liquid repellency forthe liquid material 30 is formed on the above region 42, or the like.

Hereinafter, these methods <I> and <II> will be described one afteranother.

<I> The method in which the liquid repellent functional groups areintroduced to the bonding film non-formation region 42 is notparticularly limited to a specific kind, but examples of the methodinclude a plasma treatment in which a treatment gas is activated(ionized or excited) by discharging it to generate plasma, and then theplasma is emitted on the bonding film non-formation region 42, and thelike.

As the treatment gas for imparting the liquid repellency to the bondingfilm non-formation region 42 of the first base member 21, a fluorineatom-containing compound gas such as CF₄, C₂F₆, C₃F₆, CClF₃ and SF₆ canbe used.

By using such a fluorine atom-containing compound gas as the treatmentgas, fluorine atom-containing functional groups such as fluoroalkylgroups are introduced to the bonding film non-formation region 42. As aresult, the bonding film non-formation region 42 can exhibit excellentliquid repellency for the liquid material 30.

In the case where the liquid material 30 containing the siliconematerial has water repellency (hydrophobicity), the bonding filmnon-formation region 42 can have the liquid repellency for the liquidmaterial 30 by imparting water wettability (hydrophilicity) thereto.

In this case, as a treatment gas for imparting the water wettability tothe bonding film non-formation region 42 of the first base member 21, anoxygen atom-containing gas such a O₃ gas, a H₂O gas or air, a nitrogenatom-containing gas such a N₂ gas or a NH₃ gas and a sulfuratom-containing gas such a SO₂ gas or a SO₃ gas can be used.

By using such a gas as the treatment gas, water wettable functionalgroups (hydrophilic functional groups) such as carbonyl groups, hydroxylgroups and amino groups can be introduced to the bonding filmnon-formation region 42. This makes it possible to make surface energyof the bonding film non-formation region 42 high.

As a result, a water wettable surface (a hydrophilic surface), that is,the liquid repellent region 43 exhibiting the liquid repellency for theliquid material 30 can be formed on the bonding film non-formationregion 42.

In this regard, such a plasma treatment can be carried out by placing amask provided with a window portion having a shape corresponding to thatof the bonding film non-formation region 42 on the first base member 21,and then emitting the plasma, which is generated using the abovetreatment gas, on the bonding film non-formation region 42 through themask.

By doing so, the plasma makes contact with the bonding filmnon-formation region 42 selectively so that the liquid repellency forthe liquid material 30 can be formed thereon.

<II> Examples of the liquid repellent film 431 to be formed on thebonding film non-formation region 42 include a self-assembledmonomolecular (SAM) film formed using molecules each having at least onebonding functional group that can be reacted with an atom existing inthe vicinity of the bonding surface 23 of the first base member 21 whichis a foundation of the liquid repellent film 431, a plasmapolymerization film and the like.

By forming the liquid repellent film 431 from such a film, it ispossible to effectively obtain a dense and homogeneous liquid repellentfilm 431. The self-assembled film having the liquid repellency can beformed by supplying molecules each having the at least one bondingfunctional group and at least one liquid repellent functional group ontothe bonding film non-formation region 42 of the first base member 21,and bonding the molecules to the bonding film non-formation region 42through the bonding functional group.

Hereinafter, the molecule having the bonding functional group and therepellent functional group will be described. Here, the aboveself-assembled film is a film which is formed with the above moleculesassembling autonomously on a surface of solid.

The bonding functional group is a functional group for bonding to thesurface of the solid (the bonding surface 23 of the first base member21). It is preferred that the molecule has a plurality of the bondingfunctional groups. In this case, the molecule can be firmly bonded tothe bonding film non-formation region 42 of the first base member 21 viathe plurality of bonding functional groups.

The bonding functional group is not particularly limited to a specifictype, as long as it can be bonded to the first base member 21.

For example, in the case where the base member 21 is formed of thevarious kinds of metal-based materials, the various kinds ofsilicon-based materials, the various kinds of glass-based materials orthe like as a major component thereof, and the hydroxyl groups areexposed on the bonding surface 23 thereof, a bonding functional groupincluding a hydrolysable group such as an alkoxy group or a halogengroup, an amino group or the like is preferably selected.

Further, in the case where the base member 21 is formed of noble metalas a major component thereof, a bonding functional group including athiol group is preferably selected.

In addition, in the case where the molecule has the plurality of bondingfunctional groups, it is preferred that the bonding functional groupsinclude at least one hydrolysable group. In this case, the molecules canbe not only bonded to the bonding film non-formation region 42 of thefirst base member 21, but also bonded together via the hydrolysablegroups.

This makes it possible to form network-like bonds (a network structure)due to bonding between the molecules on the bonding film non-formationregion 42 of the first base member 21. Therefore, the formed liquidrepellent film 431 can become more dense. As a result, the liquidrepellent film 431 can have especially high liquid repellency andimprove a bonding force thereof with respect to the bonding filmnon-formation region 42 of the first base member 21.

On the other hand, examples of the repellent functional group include afunctional group including a fluoroalkyl group, an alkyl group, a vinylgroup or the like. Among them, the functional group including thefluoroalkyl group is especially preferably selected. This is because thefunctional group including the fluoroalkyl group has especiallyexcellent liquid repellency.

A weight average molecular weight of the repellent functional group ispreferably in the range of about 200 to 4,000, and more preferably inthe range of about 1,000 to 2,000.

Considering the above matters, in the case where the hydroxyl groups areexposed on the bonding surface 23 of the first base member 21, variouskinds of metal alkoxides each having the functional group including thefluoroalkyl group and a metal atom such as Ti, Li, Si, Na, K, Mg, Ca,St, Ba, Al, In, Ge, Bi, Fe, Cu, Y, Zr or Ta are preferably used as themolecule for forming the self-assembled film.

Among them, in general, coupling agents (metal alkoxides) each havingthe functional group including the fluoroalkyl group and the metal atomsuch as Si, Ti or Al are more preferably used. Especially, asilane-based coupling agent (a metal alkoxide) having the functionalgroup including the fluoroalkyl group and Si is preferably used.

This is because the silane-based coupling agent having the functionalgroup including the fluoroalkyl group is chemically stable, and isavailable with ease for a reason that it is low in price.

Here, the silane-based coupling agent having the functional groupincluding the fluoroalkyl group is represented by a general formula:R_(n)SiX_((4-n)), wherein the X is a hydrolysable group that can producea silanol group by hydrolysis thereof, and the n is an integer of 1 to 3and preferably an integer of 1 or 2. In the general formula, examples ofthe X include a methoxy group, an ethoxy group, a halogen group and thelike.

In this regard, each of the Rs or each of the Xs bonded to a single Siatom may be the same or different from each other. Concrete examples ofthe silane-based coupling agent having the functional group includingthe fluoroalkyl group include tridecafluoro-1, 1, 2, 2-tetrahydrooctyltriethoxysilane, tridecafluoro-1, 1, 2, 2-tetrahydrooctyltrimethoxysilane, tridecafluoro-1, 1, 2, 2-tetrahydrooctyltrichlorosilane, trifluoropropyl trimethoxysilane and the like.

Further, although the self-assembled film can be formed using a vaporphase process, a liquid phase process or the like, it is preferred thatthe self-assembled film is formed using the liquid phase process. Byusing the liquid phase process, the self-assembled film can be reliablyformed trough a relatively simple process in which a treatment liquidcontaining the above molecules is prepared, this treatment liquid issupplied onto the bonding film non-formation region 42 of the first basemember 21, and then the treatment liquid is, if needed, subjected to apost-treatment such as a heating treatment.

Examples of a method of supplying the treatment liquid onto the bondingfilm non-formation region 42 of the first base member 21 include variouskinds of application methods such as an ink jet method, a spin coatingmethod, a casting method, a micro-gravure coating method, a gravurecoating method, a bar coating method, a roll coating method, a wire-barcoating method, a dip coating method, a spray coating method, a screenprinting method, a flexo printing method, an offset printing method, amicro-contact printing method, and the like, one of these methods may beused independently or two or more of these methods may be used incombination.

Among them, it is preferred that the ink jet method is used. Accordingto the ink jet method, it is possible to selectively and relativelyeasily supply the treatment liquid onto the bonding film non-formationregion 42 of the first base member 21 with excellent accuracy.

Further, the post-treatment is carried out, for example, for the purposeof progressing reaction between the bonding functional group and thebonding surface 23 of the first base member 21.

Hereinafter, description will be made on a case that the silane-basedcoupling agent having the functional group including the fluoroalkylgroup is used as the molecule.

In this case, when a treatment liquid containing the silane-basedcoupling agents is selectively supplied onto the bonding filmnon-formation region 42 of the first base member 21 using, for example,the ink jet method, and then the treatment liquid is heated trough thefirst base member 21, the hydrolysable groups of the silane-basedcoupling agents are hydrolyzed to generate the silanol groups, and thegenerated silanol groups are reacted with hydroxyl groups exposing onthe bonding surface 23 of the first base member 21 to form siloxanebonds.

In this way, a liquid repellent film 431 having a shape corresponding tothat of the bonding film non-formation region 42 is formed on thebonding surface 23 of the first base member 21. In such a liquidrepellent film 431, the liquid repellent functional groups are exposedon a surface (an opposite surface from the first base member 21)thereof. As a result, the liquid repellent film 431 can exhibit theliquid repellency for the liquid material 30.

On the other hand, the plasma polymerization film can be formed on thebonding film non-formation region 42 of the first base member 21 byactivating gas molecules constituting a raw gas by plasma, andpolymerizing the activated gas molecules near the bonding filmnon-formation region 42.

Examples of the raw gas for forming the plasma polymerization filmhaving the liquid repellency include a fluorine-based gas such as a CHF₃gas, a C₂F₄ gas, a C₂F₆ gas or a C₄F₈ gas. Gas molecules constitutingthe fluorine-based gas are polymerized by a plasma polymerization sothat a dense polymerized matter containing fluorine atoms can be formed.

Among them, a fluorine-based gas containing at least one kind of theCHF₃ gas, the C₂F₆ gas and the C₄F₈ gas as a major component thereof ispreferably used. This is because gas molecules constituting such afluorine-based gas can be easily polymerized by the plasmapolymerization to thereby form a dense polymerized matter havingexcellent liquid repellency.

Further, since an amount of fluorine atoms contained in each of gasmolecules constituting the fluorine-based gas is large, it is possibleto obtain a polymerized matter having higher liquid repellency.

In this regard, the raw gas may be composed of a gas generated byvaporizing a raw liquid containing fluorine atoms as a major componentthereof. There is an advantage that such a raw liquid is easy to use.

In the case where the liquid material 30 containing the siliconematerial has water repellency (hydrophobicity), the bonding filmnon-formation region 42 can have the liquid repellency for the liquidmaterial 30 by forming a plasma polymerization film having waterwettability (hydrophilicity) thereon.

Examples of a raw gas for forming the plasma polymerization film havingthe water wettability include a gas produced by vaporizing monomers eachhaving a water wettable group such as acrylic acid monomers each havingthe water wettable group and methacrylic acid monomers each having thewater wettable group.

Such a plasma polymerization film can be formed on the bonding filmnon-formation region 42 of the first base member 21 by placing a maskprovided with a window portion having a shape corresponding to that ofthe bonding film non-formation region 42 on the first base member 21,and then plasma polymerizing the above mentioned raw gas on the bondingfilm non-formation region 42 through the mask.

In this way, the plasma polymerization film is selectively formed on thebonding film non-formation region 42 so that the liquid repellent film431 is obtained thereon.

Further, in an alternative method, the plasma polymerization film isformed on the entire of the bonding surface 23 of the first base member21, a mask provided with a window portion having an opposite shape fromthat of the bonding film non-formation region 42 (a shape correspondingto that of the bonding film formation region 41) is placed on the plasmapolymerization film, and then the plasma polymerization film is etchedthrough the mask.

In this way, the plasma polymerization film is etched so as to have theshape corresponding to that of the bonding film non-formation region 42to thereby obtain the liquid repellent film 431 which selectively coversthe bonding film non-formation region 42.

Examples of a method of etching the plasma polymerization film to beused in this case include various kinds of etching methods such as a dryetching method (e.g., a plasma etching method) and a wet etching method,but the plasma etching method is preferably used.

Use of the plasma etching method makes it possible to perform patterningof the plasma polymerization film while preventing contamination of theplasma polymerization film, the first base member 21 and the like.

As a gas for etching (an etchant) to be used in the plasma etchingmethod, a fluorine-based gas is preferably used, and a gas containing aCF₄ gas as a major component thereof is more preferably used. Moleculesconstituting the CF₄ gas are easily dissociated into a carbon atom andfluorine atoms, when performing the plasma etching, to generateactivated species (activated molecules).

Due to an action (e.g., a reaction or a collision) of these activatedspecies with respect to the plasma polymerization film (a polymerizedmatter), an unnecessary portion thereof is removed so that the plasmapolymerization film can be effectively patterned.

In addition, in this case, when the plasma etching is carried out, thefluorine atoms are newly introduced into the plasma polymerization film.Therefore, it is possible to improve the liquid repellency of theobtained liquid repellent film 431. Namely, it is possible to impartmore high liquid repellency to the bonding film non-formation region 42of the first base member 21.

By using the above methods <I> and <II>, the liquid repellency isimparted to the bonding film non-formation region of the first basemember 21 to thereby form the liquid repellent region 43 thereon.According to these methods, even if the bonding film non-formationregion 42 has a complex pattern (shape), the liquid repellent region 43can be easily formed thereon.

In this regard, in this embodiment, the liquid repellent region 43 isformed so as to surround the bonding film formation region 41.

In the case where the liquid repellent region 43 has such a pattern(shape), the liquid material 30 supplied onto the bonding surface 23 ofthe first base member 21 can reliably stay within the bonding filmformation region 41 to thereby form the liquid coating 31. In this way,it is possible to reliably form a liquid coating 31 having a shapecorresponding to that of the bonding film formation region 41.

Although such a liquid repellency is imparted to the bonding filmnon-formation region 42 of the first base member 21 to thereby form theliquid repellent region 43 thereon, it is also preferred that liquidwettability for the liquid material is imparted to the bonding filmformation region 41 of the first base member 21.

When the liquid material 30 is supplied onto the bonding surface 23 inthe step which will be described below, the liquid material 30 isrepelled due to the liquid repellency of the liquid repellent region 43while being gathered onto the bonding film formation region 41 due tothe liquid wettability thereof. As a result, the liquid material 30 canbe selectively supplied onto the bonding film formation region 41.

Namely, it is preferred that the bonding film formation region 41 andthe bonding film non-formation region 42 have different affinities withrespect to the liquid material 30 with each other by appropriatelyselecting treatments to which the two regions 41 and 42 are to besubjected.

Examples of a method of imparting the liquid wettability to the bondingfilm formation region 41 include a method in which liquid wettablefunctional groups (a liquid wettable substance) are introduced into thebonding film formation region 41 to thereby impart the liquidwettability thereto, a method in which a liquid wettable film is formedon the bonding film formation region 41, and the like.

The liquid wettable functional groups are appropriately selecteddepending on a property of the liquid material 30. In the case where theliquid material 30 has hydrophobicity, a hydrophobic functional groupsuch as an alkyl group (e.g., a methyl group, an ethyl group, anisopropyl group, a butyl group or an isobutyl group) and an aryl group(e.g., a phenyl group or a naphthyl group) is selected. On the otherhand, in the case where the liquid material 30 has hydrophilicity, ahydrophilic functional group such as a hydroxyl group, a carbonyl groupand an amino group is selected.

A method of introducing such a hydrophobic or hydrophilic functionalgroup to the bonding film formation region 41 is not particularlylimited to a specific kind, as long as the functional groups can beintroduced thereto by utilizing application of energy, but examples ofthe method include a plasma treatment in which a treatment gas isactivated (ionized or excited) by discharging it to generate plasma, andthen the plasma is emitted on the bonding film formation region 41, andthe like.

Further, by subjecting the bonding film formation region 41 to anoxidation treatment, the hydroxyl groups can be easily introducedthereto. The oxidation treatment can be carried out using a simplemethod such as a method in which the bonding film formation region 41 ofthe first base member 21 is heated or a method in which an ultravioletray is irradiated on the bonding film formation region 41 of the firstbase member 21.

Alternatively, the liquid wettability may be imparted to the bondingfilm formation region 41 by forming a coating having hydrophilicity orhydrophobicity thereon. Such a coating can be formed from, for example,a self-assembled film, a plasma polymerization film or the like.

Further, irregularities may be formed on the bonding film formationregion 41 by subjecting it to a surface roughening treatment. In thiscase, since adhesion of the liquid material 30 with respect to bondingfilm formation region is enhanced due to existence of theirregularities, it is also possible to impart the liquid wettability forthe liquid material 30 to the bonding film formation region 41. Examplesof the surface roughening treatment include a sputtering treatment, ablast treatment and the like.

[3] Next, as shown in FIG. 1C, the liquid material 30 containing thesilicone material is supplied onto the bonding surface 23 of the firstbase member 21 to form the liquid coating 31 on the bonding filmformation region 41.

As a method of supplying the liquid material 30, the same method asdescribed in the above step [2] can be used. In this regard, byappropriately adjusting an amount of the liquid material 30 to besupplied onto the bonding surface 23 at this time, it is possible torelatively easily control a thickness of the bonding film 3 to beformed.

When the liquid material 30 is supplied onto the bonding surface 23 ofthe first base member 21, since the liquid repellent region 43 is formedon the bonding film non-formation region 42, the liquid material 30hardly adheres to the bonding film non-formation region 42 by repellingit due to the liquid repellency thereof.

On the other hand, the liquid material 30 directly supplied onto thebonding film formation region 41 adheres thereto. Further, the liquidmaterial 30 repelled due to the liquid repellency of the bonding filmnon-formation region 42 moves toward the bonding film formation region41 and also adheres thereto.

Namely, the liquid material 30 is self-aligned so that a liquid coating31 having a pattern (shape) corresponding to that of the bonding filmformation region 41 is selectively formed on the bonding surface 23 ofthe first base member 21.

In the case where the liquid repellency for the liquid material 30 isimparted to the bonding film non-formation region 42, even if the liquidmaterial 30 is supplied onto the entire of the bonding surface 23 of thefirst base member 21, it can autonomously and selectively adhere to thebonding film formation region 41.

Therefore, even if an application method such as a spin coating method,which is relatively easily used but is difficult to control a regionwhere a liquid material is to be supplied, is used, a liquid coating 31having a predetermined shape can be formed without a mask or the like.For this reason, a step of forming the liquid coating 31 can besimplified and a time required for forming the liquid coating 31 can beshortened.

Further, even if a large amount of the liquid material 30 is suppliedonto the bonding film formation region 41, the liquid material 30 hardlyflows toward the bonding film non-formation region 42. This makes itpossible to prevent extension of the liquid coating 31. As a result, athickness of the finally obtained bonding film 3 becomes larger.

Furthermore, the liquid coating 31 can be also formed by performing theabove step several times. This makes it possible to further extend acontrollable range of the thickness of the bonding film 3. This alsomakes it possible to control the thickness and shape of the bonding film3 with high accuracy.

Here, the liquid material 30 contains the silicone material composed ofthe silicone compounds.

“silicone material” means a material composed of silicone compounds(molecules) each having a polyorganosiloxane chemical structure, thatis, silicone compounds each having a main chemical structure (a mainchain) mainly constituted of organosiloxane repeating units.

Each of the silicone compounds contained in the silicone material mayhave a branched chemical structure including a main chain and sidechains each branched therefrom, a ringed chemical structure in which themain chain forms a ring shape, or a straight chemical structure in whichboth ends of the main chain are not bonded together.

In each silicone compound having the polyorganosiloxane chemicalstructure, for example, an organosiloxane repeating unit constitutingeach end portion of the polyorganosiloxane chemical structure is arepeating unit represented by the following general formula (1), anorganosiloxane repeating unit constituting each connecting portion ofthe polyorganosiloxane chemical structure is a repeating unitrepresented by the following general formula (2), and an organosiloxanerepeating unit constituting each branched portion of thepolyorganosiloxane chemical structure is a repeating unit represented bythe following general formula (3).

wherein in the general formulas (1) to (3), each of the Rs isindependently a substituted hydrocarbon group or an unsubstitutedhydrocarbon group, each of the Zs is independently a hydroxyl group or ahydrolysable group, each of the Xs is a siloxane residue, the a is 0 oran integer of 1 to 3, the b is 0 or an integer of 1 to 2, and the c is 0or 1.

In this regard, the siloxane residue means a substituent group which isbonded to a silicon atom contained in an adjacent repeating unit via anoxygen atom to thereby form a siloxane bond. Specifically, the siloxaneresidue is a chemical structure of —O—(Si), wherein the Si is thesilicon atom contained in the adjacent repeating unit.

In each silicone compound, the polyorganosiloxane chemical structure ispreferably the straight chemical structure, that is, a chemicalstructure constituted of the repeating units each represented by theabove general formula (1) and the repeating units each represented bythe above general formula (2).

In the case where a silicone material composed of such siliconecompounds is used, since in the following step, the silicone compoundsare tangled together in the liquid material 30 (the liquid coating 31)so that the bonding film 3 is formed, the thus formed bonding film 3 canhave excellent film strength.

Specifically, examples of the silicone compound having such apolyorganosiloxane chemical structure include a silicone compoundrepresented by the following general formula (4).

Wherein in the general formula (4), each of the Rs is independently asubstituted hydrocarbon group or an unsubstituted hydrocarbon group,each of the Zs is independently a hydroxyl group or a hydrolysablegroup, the a is 0 or an integer of 1 to 3, the m is 0 or an integer of 1or more, and the n is 0 or an integer of 1 or more.

In the general formulas (1) to (4), examples of the R (the substitutedhydrocarbon group or unsubstituted hydrocarbon group) include: an alkylgroup such as a methyl group, an ethyl group or a propyl group; acycloalkyl group such as a cyclopentyl group or a cyclohexyl group; anaryl group such as a phenyl group, a tolyl group or a biphenylyl group;and an aralkyl group such as a benzyl group or a phenyl ethyl group.

Further, in the above groups, a part of or all of hydrogen atoms bondingto carbon atom(s) may be respectively substituted by I) a halogen atomsuch as a fluorine atom, a chlorine atom or a bromine atom, II) an epoxygroup such as a glycidoxy group, III) a (meth)acryloyl group such as anmethacryl group, IV) an anionic group such as a carboxyl group or asulfonyl group, and the like.

Examples of the hydrolysable group include: an alkoxy group such as amethoxy group, an ethoxy group, a propoxy group, a butoxy group; aketoxime group such as a dimethyl ketoxime group or a methyl ethylketoxime group; an acyloxy group such as an acetoxy group; an alkenyloxygroup such as an isopropenyloxy group or an isobutenyloxy group; and thelike.

Further, in the general formula (4), the m and n represent a degree ofpolymerization of the polyorganosiloxane chemical structure. The totalnumber of the m and n (that is, m+n) is preferably an integer of about 5to 10,000, and more preferably an integer of about 50 to 1,000. Bysetting the degree of the polymerization to the above range, a viscosityof the liquid material 30 can be relatively easily adjusted to a rangewhich will be described below.

Among various kinds of the silicone materials, it is preferable to use asilicone material composed of silicone compounds each having apolydimethylsiloxane chemical structure (that is, a chemical structurerepresented by the above general formula (4) in which the Rs are themethyl groups) as a main chemical structure thereof. Such siliconecompounds can be relatively easily available at a low price.

Further, such silicone compounds can be preferably used as a majorcomponent of the silicone material because the methyl groups are easilybroken and removed from their chemical structures by applying energy.Therefore, in the case where the bonding film 3 contains such a siliconematerial, when applying the energy to the bonding film 3 in thesubsequent step, it is possible for the bonding film 3 to reliablydevelop the bonding property.

In addition, it is preferred that each of the silicone compounds has atleast one silanol group. Specifically, it is preferable to use siliconecompounds each having a chemical structure represented by the abovegeneral formula (4) in which the Zs are the hydroxyl groups.

In the case where the bonding film 3 is formed using the siliconematerial composed of such silicone compounds, when drying the liquidcoating 30 to transform it into the bonding film 3 in the followingstep, the hydroxyl groups (included in the silanol groups) of theadjacent silicone compounds are bonded together. Therefore, the thusformed bonding film 3 can have more excellent film strength.

In addition, in the case where the first base member 21 described above,in which the hydroxyl groups are exposed on the bonding surface 23, isused, the hydroxyl groups (included in the silanol groups) of thesilicone compounds and the hydroxyl groups present in the first basemember 21 are bonded together.

As a result, the silicone compounds can be bonded to the bonding surface23 not only through physical bonds but also through chemical bonds. Thismakes it possible for the bonding film 3 to be firmly bonded to thebonding surface 23 of the first base member 21.

Further, the silicone material is a material having relatively highflexibility. Therefore, even if the constituent material of the firstbase member 21 is different from that of the second base member 22, whenthe bonded body 1 is obtained by bonding them together through thebonding film 3 in the subsequent step, the bonding film 3 can reliablyreduce stress which would be generated between the first and second basemembers 21 and 22 due to thermal expansions thereof. As a result, it ispossible to reliably prevent occurrence of peeling in the bonded body 1finally obtained.

Since the silicone material also has excellent chemical resistance, itcan be effectively used in bonding members, which are exposed tochemicals for a long period of time, together. Specifically, forexample, the bonding film 3 according to the present invention can beused in manufacturing a liquid droplet ejection head of a commercial inkjet printer in which an organic ink being apt to erode a resin materialis employed. This makes it possible to reliably improve durability ofthe liquid droplet ejection head.

In addition, since the silicone material has excellent heat resistance,it can also be effectively used in bonding members, which are exposed toa high temperature, together.

A viscosity (at 25° C.) of the liquid material 30 is, generally,preferably in the range of about 0.5 to 200 mPa·s, and more preferablyin the range of about 3 to 20 mPa·s.

By adjusting the viscosity of the liquid material 30 to the range notedabove, even if the liquid material 30 is supplied onto the liquidrepellent region 43 (the bonding film non-formation region 42), itrapidly moves toward the bonding film formation region 41 and isaccumulated thereon. As a result, it is possible to selectively obtain aliquid coating 31 having a correct shape corresponding to that of thebonding film formation region 41.

Further, in this case, since the liquid material 30 can have arelatively high viscosity, it is possible to form a liquid coating 31having a thicker thickness. In addition, such a liquid material 30 cancontain a sufficient amount of the silicone material therein. Therefore,by drying the liquid coating 31 formed of such a liquid material 30 inthe following step [4], the bonding film 3 can be formed reliably.

In this regard, if the viscosity of the liquid material 30 is lower thanthe lower limit value, flowability thereof becomes remarkably high. As aresult, there is a fear that the liquid material 30 flows toward thebonding film non-formation region 42 from the bonding film formationregion 41.

On the other hand, if the viscosity of the liquid material 30 exceedsthe upper limit value, the flowability thereof becomes low. As a result,there is a fear that accuracy of the thickness and shape of the liquidcoating 31 is remarkably lowered.

As described above, although the liquid material 30 contains thesilicone material, in the case where the silicone material itself is inthe form of liquid and has a required viscosity range, the siliconematerial can be used as the liquid material 30 directly. On the otherhand, in the case where the silicone material itself is in the form ofsolid or liquid having a high viscosity, a solution or dispersion liquidcontaining the silicone material can be used as the liquid material 30.

Examples of a solvent dissolving the silicone material or a dispersionmedium for dispersing the same include: various kinds of inorganicsolvents such as ammonia, water, hydrogen peroxide, carbon tetrachlorideand ethylene carbonate; various kinds of organic solvents such asketone-based solvents (e.g., methyl ethyl ketone (MEK) and acetone),alcohol-based solvents (e.g., methanol, ethanol and isopropanol),ether-based solvents (e.g., diethyl ether and diisopropyl ether),cellosolve-based solvents (e.g., methyl cellosolve), aliphatichydrocarbon-based solvents (e.g., hexane and pentane), aromatichydrocarbon-based solvents (e.g., toluene, xylene and benzene), aromaticheterocycle compound-based solvents (e.g., pyridine, pyrazine andfuran), amide-based solvents (e.g., N,N-dimethylformamide), halogencompound-based solvents (dichloromethane and chloroform), ester-basedsolvents (e.g., ethyl acetate and methyl acetate), sulfur compound-basedsolvents (e.g., dimethyl sulfoxide (DMSO) and sulfolane), nitrile-basedsolvents (e.g., acetonitrile, propionitrile and acrylonitrile), organicacid-based solvents (e.g., formic acid and trifluoroacetic acid);mixture solvents each containing at least one kind of the abovesolvents; and the like.

[4] Next, the liquid coating 31 formed on the bonding film formationregion 41 of the first base member 21 is dried. In this way, as shown inFIG. 1D, a bonding film 3 having a predetermined pattern which is of ashape corresponding to that of the bonding film formation region 41 isformed.

The bonding film 3 formed in this way can develop a bonding propertywhen applying energy thereto. Further, in the case where the siliconematerial composed of the silicone compounds each having the at least onesilanol group is used, the hydroxyl groups included in the silanolgroups of the silicone compounds are reliably bonded together.

In addition, such hydroxyl groups and the hydroxyl groups present in thefirst base member 21 are reliably bonded together. For these reasons,the thus formed bonding film 3 can have excellent film strength and befirmly bonded to the first base member 21.

A drying temperature of the liquid coating 31 is preferably 25° C. orhigher, and more preferably in the range of about 25 to 100° C. Further,a drying time of the liquid coating 31 is preferably in the range ofabout 0.5 to 48 hours, and more preferably in the range of about 15 to30 hours.

An ambient pressure in drying the liquid coating 31 may be anatmospheric pressure, but is preferably a reduced pressure.Specifically, a degree of the reduced pressure is preferably in therange of about 133.3×10⁻⁵ to 1,333 Pa (1×10⁻⁵ to 10 Torr), and morepreferably in the range of about 133.3×10⁻⁴ to 133.3 Pa (1×10⁻⁴ to 1Torr).

This makes it possible to progress the drying of the liquid coating 31.Further, this also makes it possible to improve density of the bondingfilm 3, that is, the bonding film 3 can become dense. As a result, thebonding film 3 can have more excellent film strength.

In this way, by appropriately controlling the conditions in forming thebonding film 3, it is possible to form a bonding film 3 having a desiredfilm strength and the like.

An average thickness of the bonding film 3 is preferably in the range ofabout 100 nm to 100 μm, and more preferably in the range of about 200 nmto 10 μm. By setting the average thickness of the formed bonding film 3to the above range, it is possible to prevent dimensional accuracy ofthe bonded body 1 obtained by bonding the first base member 21 and thesecond base member 22 together from being significantly lowered, therebyenabling to firmly bond them together.

In this regard, setting of the average thickness of the bonding film 3can be performed by appropriately controlling an amount of the liquidmaterial 30 to be supplied onto the first base member 21.

In this regard, if the average thickness of the bonding film 3 is lowerthan the above lower limit value, there is a case that the bonded body 1having sufficient bonding strength between the first base member 21 andthe second base member 22 cannot be obtained. In contrast, if theaverage thickness of the bonding film 3 exceeds the above upper limitvalue, there is a fear that dimensional accuracy of the bonded body 1 islowered significantly.

Further, by setting the average thickness of the bonding film 3 to theabove range, the bonding film 3 can have a certain degree of elasticity.Therefore, when the first base member 21 and the second base member 22are bonded together, even if particles or the like adhere (exist) on thebonding surface 24 of the second base member 22 which makes contact withthe bonding film 3, the bonding film 3 takes into the particles so thatit can reliably bond to the second base member 22.

As a result, it is possible to reliably suppress or prevent reduction ofthe bonding strength between the bonding film 3 and the second basemember 22 and occurrence of peeling of the bonding film 3 from thesecond base member 22 in an interface thereof, due to the existence ofthe particles.

[5] Next, the energy is applied to the bonding film 3. When the energyis applied to the bonding film 3, a part of molecular bonds of thesilicone compounds present in the vicinity of the surface of the bondingfilm 3 are broken. As a result, the surface is activated due to breakageof the molecular bonds. Namely, the bonding property with respect to thesecond base member 22 is developed in the vicinity of the surface of thebonding film 3.

The first base member 21 having the bonding film 3 in such a state canbe firmly bonded to the second base member 22 based on chemical bonds.

Here, in this specification, a state that the surface of the bondingfilm 3 is “activated” means: a state that a part of the molecular bondsof the silicone compounds present in the vicinity of the surface arebroken as described above, e.g., a part of the methyl groups are brokenand removed from the polydimethylsiloxane chemical structure, and a partof the silicon atoms are not terminated so that “dangling bonds (oruncoupled bonds)” are generated on the surface; a state that the siliconatoms having the dangling bonds (the unpaired electrons) are terminatedby hydroxyl groups (OH groups) so that the hydroxyl groups exist on thesurface; and a state that the dangling bonds and the hydroxyl groupscoexist on the surface.

The energy may be applied to the bonding film 3 by any method. Examplesof the method include: a method in which an energy beam is irradiated onthe bonding film 3; a method in which the bonding film 3 is heated; amethod in which a compressive force (physical energy) is applied to thebonding film 3; a method in which the bonding film 3 is exposed toplasma (that is, plasma energy is applied to the bonding film 3); amethod in which the bonding film 3 is exposed to an ozone gas (that is,chemical energy is applied to the bonding film 3); and the like.

This makes it possible to effectively activate the surface of thebonding film 3. This also makes it possible to prevent excessivebreakage of the molecular bonds of the silicone compounds contained inthe bonding film 3. Therefore, it is possible to prevent a property ofthe bonding film 3 from being lowered.

Among the above methods, in this embodiment, it is particularlypreferred that the method in which the energy beam is irradiated on thebonding film 3 is used as the method in which the energy is applied tothe bonding film 3. Since such a method can efficiently apply the energyto the bonding film 3 relatively easily, the method is suitably used asthe method of applying the energy.

Examples of the energy beam include: a ray such as an ultraviolet ray ora laser beam; an electromagnetic wave such as a X ray or a γ ray; aparticle beam such as an electron beam or an ion beam; and combinationsof two or more kinds of these energy beams.

Among these energy beams, it is particularly preferred that anultraviolet ray having a wavelength of about 126 to 300 nm is used (seeFIG. 1E). Use of the ultraviolet ray having such a wavelength makes itpossible to optimize an amount of the energy to be applied to thebonding film 3.

As a result, it is possible to prevent excessive breakage of themolecular bonds of the silicone compounds constituting a main portion (atrunk portion) of the bonding film 3, and to selectively break themolecular bonds of the silicone compounds present in the vicinity of thesurface of the bonding film 3. This makes it possible for the bondingfilm 3 to develop the bonding property, while preventing a propertythereof such as a mechanical property or a chemical property from beinglowered.

Further, the use of the ultraviolet ray makes it possible to process awide area of the surface of the bonding film 3 without unevenness in ashort period of time. Therefore, the breakage of the molecular bonds ofthe silicone compounds present in the vicinity of the surface of thebonding film 3 can be efficiently performed. Moreover, such anultraviolet ray has, for example, an advantage that it can be generatedby simple equipment such as an UV lamp.

In this regard, it is to be noted that the wavelength of the ultravioletray is more preferably in the range of about 126 to 200 nm.

In the case where the UV lamp is used, power of the UV lamp ispreferably in the range about of 1 mW/cm² to 1 W/cm², and morepreferably in the range of about 5 to 50 mW/cm², although beingdifferent depending on an area of the surface of the bonding film 3. Inthis case, a distance between the UV lamp and the bonding film 3 ispreferably in the range of about 3 to 3,000 mm, and more preferably inthe range of about 10 to 1,000 mm.

Further, a time for irradiating the ultraviolet ray is preferably set toa time enough for selectively breaking the molecular bonds of thesilicone compounds present in the vicinity of the surface of the bondingfilm 3.

Specifically, the time is preferably in the range of about 1 second to30 minutes, and more preferably in the range of about 1 second to 10minutes, although being slightly different depending on an amount of theultraviolet ray, the constituent material of the bonding film 3, and thelike.

The ultraviolet ray may be irradiated temporally continuously orintermittently (in a pulse-like manner).

On the other hand, examples of the laser beam include: a pulseoscillation laser (a pulse laser) such as an excimer laser; a continuousoscillation laser such as a carbon dioxide laser or a semiconductorlaser; and the like. Among these lasers, it is preferred that the pulselaser is used.

Use of the pulse laser makes it difficult to accumulate of heat in aportion of the bonding film 3 where the laser beam is irradiated withtime. Therefore, it is possible to reliably prevent alteration anddeterioration of the bonding film 3 due to the heat accumulated. Namely,according to the use of the pulse laser, it is possible to preventaffection of the heat accumulated inside the bonding film 3.

In the case where influence of the heat is taken into account, it ispreferred that a pulse width of the pulse laser is as small as possible.Specifically, the pulse width is preferably equal to or smaller than 1ps (picosecond), and more preferably equal to or smaller than 500 fs(femtoseconds).

By setting the pulse width to the above range, it is possible toreliably suppress the influence of the heat generated in the bondingfilm 3 due to the irradiation with the laser beam. In this regard, it isto be noted that the pulse laser having the small pulse width of theabove range is called “femtosecond laser”.

A wavelength of the laser beam is not particularly limited to a specificvalue, but is preferably in the range of about 200 to 1,200 nm, and morepreferably in the range of about 400 to 1,000 nm. Further, in the caseof the pulse laser, peak power of the laser beam is preferably in therange of about 0.1 to 10 W, and more preferably in the range of about 1to 5 W, although being different depending on the pulse width thereof.

Moreover, a repetitive frequency of the pulse laser is preferably in therange of about 0.1 to 100 kHz, and more preferably in the range of about1 to 10 kHz. By setting the frequency of the pulse laser to the aboverange, the molecular bonds of the silicone compounds present in thevicinity of the surface of the bonding film 3 can be selectively broken.

By appropriately setting various conditions for such a laser beam, thetemperature in the portion where the laser beam is irradiated isadjusted so as to be preferably in the range of about normal temperature(room temperature) to 600° C., more preferably about in the range of 200to 600° C., and even more preferably in the range of about 300 to 400°C. The adjustment of the temperature in the region to the above rangemakes it possible to selectively break the molecular bonds of thesilicone compounds present in the vicinity of the surface of the bondingfilm 3.

The laser beam irradiated on the bonding film 3 is preferably scannedalong the surface of the bonding film 3 with a focus thereof set on thesurface. By doing so, heat generated by the irradiation of the laserbeam is locally accumulated in the vicinity of the surface. As a result,it is possible to selectively break the molecular bonds of the siliconecompounds present in the vicinity of the surface of the bonding film 3.

Further, the irradiation of the energy beam on the bonding film 3 may beperformed in any ambient atmosphere. Specifically, examples of theambient atmosphere include: an oxidizing gas atmosphere such as air oran oxygen gas; a reducing gas atmosphere such as a hydrogen gas; aninert gas atmosphere such as a nitrogen gas or an argon gas; adecompressed (vacuum) atmospheres obtained by decompressing any one ofthese ambient atmospheres; and the like.

Among these ambient atmospheres, the irradiation is particularlypreferably performed in the air atmosphere (particularly, an atmospherehaving a low dew point). By doing so, it is possible to generate anozone gas near the surface. This makes it possible to more smoothlyactivate the surface. Further, by doing so, it becomes unnecessary tospend a labor hour and a cost for controlling the ambient atmosphere.This makes it possible to easily perform (carry out) the irradiation ofthe energy beam.

In this way, according to the method of irradiating the energy beam, theenergy can be easily applied to the bonding film 3 selectively.Therefore, it is possible to prevent, for example, alteration anddeterioration of the first base member 21 due to the application of theenergy.

Further, according to the method of irradiating the energy beam,magnitude of the energy to be applied can be accurately and easilycontrolled. Therefore, it is possible to adjust the number of themolecular bonds to be broken within the bonding film 3. By adjusting thenumber of the molecular bonds to be broken in this way, it is possibleto easily control the bonding strength between the first base member 21and the second base member 22.

In other words, by increasing the number of the molecular bonds to bebroken in the vicinity of the surface of the bonding film 3, since alarge number of active hands are generated in the vicinity of thesurface, it is possible to further improve the bonding propertydeveloped in the bonding film 3.

On the other hand, by reducing the number of the molecular bonds to bebroken in the vicinity of the surface of the bonding film 3, it ispossible to reduce the number of the active hands generated in thevicinity of the surface, thereby suppressing the bonding propertydeveloped in the bonding film 3.

In order to adjust the magnitude of the applied energy, for example,conditions such as a kind of the energy beam, power of the energy beam,and an irradiation time of the energy beam only have to be controlled.

Further, according to the method of irradiating the energy beam, a largeamount of the energy can be applied to the bonding film 3 for a shortperiod of time. This makes it possible to more effectively perform theapplication of the energy.

[6] Next, the first base member 21 and the second base member 22 arelaminated together so that the bonding film 3 and the bonding surface 24of the second base member 22 make close contact with each other (seeFIG. 2F). At this time, since the surface of the bonding film 3 hasdeveloped the bonding property with respect to the second base member 22in the step [5], the bonding film 3 and the second base member 22 (thebonding surface 24) are chemically bonded together.

As a result, the first base member 21 and the second base member 22 arepartially bonded together through the bonding film 3 to thereby obtain abonded body 1 shown in FIG. 2G. Namely, in the bonded body 1, the firstbase member 21 and the second base member 22 are partially bondedtogether in a region where they make contact with the bonding film 3.

In the bonded body 1 obtained in this way, the two base members 21 and22 are bonded together by firm chemical bonds formed in a short periodof time such as a covalent bond, unlike bond (adhesion) mainly based ona physical bond such as an anchor effect by using the conventionaladhesive. Therefore, it is possible to obtain a bonded body 1 in a shortperiod of time, and to prevent occurrence of peeling, bonding unevennessand the like in the bonded body 1.

Further, according to such a method of manufacturing the bonded body 1,a heat treatment at a high temperature (e.g., a temperature equal to orhigher than 700° C.) is unnecessary unlike the conventional solidbonding method. Therefore, the first base member 21 and the second basemember 22 each formed of a material having low heat resistance can alsobe used for bonding them.

In addition, the first base member 21 and the second base member 22 arebonded together through the bonding film 3. Therefore, there is also anadvantage that each of the constituent materials of the base members 21and 22 is not limited to a specific kind. For these reasons, it ispossible to expand selections of the constituent materials of the firstbase member 21 and the second base member 22.

Further, a thermal expansion coefficient of the bonding film 3 is muchlower than that of the conventional adhesive. Therefore, even if anambient temperature is changed, the thickness of the bonding film 3hardly changes. As a result, the dimensional accuracy thereof becomesvery high.

Furthermore, in this embodiment, the bonding film 3 is selectivelyformed on a region of the bonding surface 23 of the first base member 21to which the second base member 22 is to be bonded. Therefore, in thecase where the first base member 21 and the second base member 22 havedifferent thermal expansion coefficients with each other, stress whichwould be generated on a bonding interface therebetween in the bondedbody 1 is suppressed to a low level compared with a bonded body in whichthe bonding film 3 is formed on the entire of the surface 23. This makesit possible to reliably prevent or suppress peeling of the first basemember 21 from the second base member 22.

In addition, in the case where the first base member and the second basemember 22 have the different thermal expansion coefficients with eachother, it is preferred that the first base member 21 and the second basemember 22 are bonded together at as low temperature as possible. If theyare bonded together at the low temperature, it is possible to furtherreduce the thermal stress which would be generated on the bondinginterface therebetween.

Specifically, the first base member 21 and the second base member 22 arebonded together in a state that each of the first base member 21 and thesecond base member 22 is heated preferably at a temperature of about 25to 50° C., and more preferably at a temperature of about 25 to 40° C.,although being different depending on the difference between the thermalexpansion coefficients thereof.

In such a temperature range, even if the difference between the thermalexpansion coefficients of the first base member 21 and the second basemember 22 is rather large, it is possible to sufficiently reduce thermalstress which would be generated on the bonding interface between thefirst base member 21 and the second base member 22. As a result, it ispossible to reliably suppress or prevent occurrence of warp, peeling orthe like in the bonded body 1.

Especially, in the case where the difference between the thermalexpansion coefficients of the first base member 21 and the second basemember 22 is equal to or larger than 5×10⁻⁵/K, it is particularlyrecommended that the first base member 21 and the second base member 22are bonded together at a low temperature as much as possible asdescribed above.

According to this embodiment, when the first base member 21 and thesecond base member 22 are not bonded together in the entire of thebonding interface therebetween, but partially bonded together throughthe bonding film 3 selectively formed on the bonding film formationregion 41. Further, a shape and a size of the bonding film 3 can beadjusted by merely controlling those of the bonding film formationregion 41.

Therefore, by controlling the shape and the size of the bonding film 3through which the first base member 21 and the second base member 22 arebonded together, it is possible to easily adjust the bonding strengththerebetween. As a result, there is provided a bonded body 1 which canbe easily separated into the first base member 21 and the second basemember 22.

Namely, by controlling the shape and the size of the bonding film 3 (thebonding film formation region 41), it is possible to adjust not only thebonding strength between the first base member 21 and the second basemember 22 but also separating strength (splitting strength)therebetween.

From this standpoint, it is preferred that, in the case of producing aneasy-to-separate bonded body 1, the bonding strength between the firstbase member 21 and the second base member 22 is set enough for the humanhands to separate the bonded body 1. By doing so, it becomes possible toeasily separate the bonded body 1 without having to use any device ortool.

By appropriately setting the shape and the size of the bonding film 3through which the first base member 21 and the second base member 22 arebonded together, it is possible to reduce local concentration of stresswhich would be generated in the bonding film 3. This makes it possibleto reliably bond the first base member 21 and the second base member 22together, even if the difference between, for example, the thermalexpansion coefficients thereof is large.

In addition, according to the method of this embodiment, as shown inFIG. 2G, between the first base member and the second base member 22 ina region on which the bonding film 3 is not formed, a gap 3 c having adistance (a size) corresponding to the thickness of the bonding film 3is formed. This means that it is possible to easily form closed spaces,flow paths or the like each having a desired shape between the firstbase member 21 and the second base member 22 by suitably controlling theshape of the bonding film 3, in order to effectively utilize the gap 3c.

Here, description will be made on a mechanism that the first base member21 and the second base member 22 are bonded together in this process.Hereinafter, description will be representatively offered regarding acase that the hydroxyl groups are exposed in the surface 24 of thesecond base member 22.

In this process, when the first base member 21 and the second basemember 22 are laminated together so that the bonding film 3 formed onthe first base member 21 makes contact with the bonding surface 24 ofthe second base member 22, the hydroxyl groups existing on the surfaceof the bonding film 3 and the hydroxyl groups existing on the bondingsurface 24 of the second base member 22 are attracted together, as aresult of which hydrogen bonds are generated between the above adjacenthydroxyl groups. It is conceived that the generation of the hydrogenbonds makes it possible to bond the first base member 21 and the secondbase member 22 together.

Depending on conditions such as a temperature and the like, the hydroxylgroups bonded together through the hydrogen bonds are dehydrated andcondensed, so that the hydroxyl groups and/or water molecules areremoved from a bonding interface between the bonding film 3 and thesecond base member 22. As a result, two atoms, to which the hydroxylgroup had been bonded, are bonded together directly or via an oxygenatom. In this way, it is conceived that the first base member 21 and thesecond base member 22 are firmly bonded together.

In addition, in the case where the dangling bonds (the uncoupled bonds)exist on the surface of the bonding film 3 and/or in the bonding film 3or on the surface 24 of the second base member 22 and/or in the secondbase member 22, when the first base member 21 and the second base member22 are laminated together, the dangling bonds are bonded together.

This bonding occurs in a complicated fashion so that the dangling bondsare inter-linked. As a result, network-like bonds are formed in thebonding interface. This makes it possible to particularly firmly bondthe bonding film 3 and the second base member 22 together.

In this regard, an activated state that the surface of the bonding film3 is activated in the step [5] is reduced with time. Therefore, it ispreferred that this step [6] is started as early as possible after thestep [5]. Specifically, this step [6] is preferably started within 60minutes, and more preferably started within 5 minutes after the step[5].

If the step [6] is started within such a time, since the surface of thebonding film 3 maintains a sufficient activated state, when the firstbase member 21 is bonded to the second base member 22 through thebonding film 3, they can be bonded together with sufficient high bondingstrength therebetween.

In other words, the bonding film 3 before being activated is a filmcontaining the silicone material as the major component thereof, andtherefore it has relatively high chemical stability and excellentweather resistance. For this reason, the bonding film 3 before beingactivated can be stably stored for a long period of time. Therefore, afirst base member 21 having such a bonding film 3 may be used asfollows.

Namely, first, a large number of the first base members 21 each havingsuch a bonding film 3 have been manufactured or purchased, and stored inadvance. Then just before each of the first base members 21 is laminatedto the second base member 22 through the bonding film 3 in this step,the energy is applied to only a necessary number of the first basemembers 21 each having such a bonding film 3 as described in the step[5]. This use is preferable because the bonded bodies 1 are manufacturedeffectively.

Through the above steps, it is possible to obtain a bonded body 1 (thebonded body of the present invention) shown in FIG. 2G.

In the bonded body 1 obtained in this way, the bonding strength betweenthe first base member 21 and the second base member 22 is preferablyequal to or larger than 5 MPa (50 kgf/cm²), and more preferably equal toor larger than 10 MPa (100 kgf/cm²). Therefore, peeling of the bondedbody 1 having such bonding strength can be sufficiently prevented.

Further, use of the method of the present invention makes it possible toefficiently manufacture the bonded body 1 in which the first base member21 and the second base member 22 are bonded together through the bondingfilm 3 with the above large bonding strength.

Just when the bonded body 1 is obtained or after the bonded body 1 hasbeen obtained, if necessary, at least one step (step of improvingbonding strength between the first base member 21 and the second basemember 22) of two steps [7A] and [7B] which will be described below maybe applied to the bonded body 1.

This makes it possible to further improve the bonding strength betweenthe first base member 21 and the second base member 22 (including thebonding strength between the first base member 21 and the bonding film 3and the bonding strength between the second base member 22 and thebonding film 3) with ease.

[7A] As shown in FIG. 2H, the obtained bonded body 1 is compressed in adirection in which the first base member 21 and the second base member22 come close to each other.

As a result, surfaces of the bonding film 3 come closer to the bondingsurface 23 of the first base member 21 and the bonding surface 24 of thesecond base member 22, respectively. It is possible to further improvethe bonding strength between the first base member 21 and the secondbase member 22 in the bonded body 1.

Further, by compressing the bonded body 1, spaces remaining in each ofthe boding interfaces in the bonded body 1 can be crashed to furtherincrease bonding areas thereof. This makes it possible to furtherimprove the bonding strength between the first base member 21 and thesecond base member 22 in the bonded body 1.

In this regard, it is to be noted that a pressure in compressing thebonded body 1 can be appropriately adjusted, depending on theconstituent materials and thicknesses of the first base member 21 andthe second base member 22, conditions of a bonding apparatus, and thelike.

Specifically, the pressure is preferably in the range of about 0.2 to 10MPa, and more preferably in the range of about 1 to 5 MPa, althoughbeing slightly different depending on the constituent materials andthicknesses of the first base member 21 and the second base member 22,and the like.

By setting the pressure to the above range, it is possible to reliablyimprove the bonding strength between the first base member 21 and thesecond base member 22 in the bonded body 1. Further, although thepressure may exceed the above upper limit value, there is a fear thatdamages and the like occur in the first base member 21 and the secondbase member 22, depending on the constituent materials thereof.

A time for compressing the bonded body 1 is not particularly limited toa specific value, but is preferably in the range of about 10 seconds to30 minutes. The compressing time can be appropriately changed, dependingon the pressure in compressing the bonded body 1.

Specifically, in the case where the pressure in compressing the bondedbody 1 is higher, it is possible to improve the bonding strength betweenthe first base member 21 and the second base member 22 in the bondedbody 1 even if the compressing time becomes short.

[7B] As shown in FIG. 2H, the obtained bonded body 1 is heated.

This makes it possible to further improve the bonding strength betweenthe first base member 21 and the second base member 22 in the bondedbody 1. A temperature in heating the bonded body 1 is not particularlylimited to a specific value, as long as the temperature is higher thanroom temperature and lower than a heat resistant temperature of thebonded body 1.

Specifically, the temperature is preferably in the range of about 25 to100° C., and more preferably in the range of about 50 to 100° C. If thebonded body 1 is heated at the temperature of the above range, it ispossible to reliably improve the bonding strength between the first basemember 21 and the second base member 22 in the bonded body 1 whilereliably preventing them from being thermally altered and deteriorated.

Further, a heating time is not particularly limited to a specific value,but is preferably in the range of about 1 to 30 minutes.

In the case where both steps [7A] and [7B] are performed, the steps arepreferably performed simultaneously. In other words, as shown in FIG.2H, the bonded body 1 is preferably heated while being compressed. Bydoing so, an effect by compressing and an effect by heating areexhibited synergistically. It is possible to particularly improve thebonding strength between the first base member 21 and the second basemember 22 in the bonded body 1.

Through the steps described above, it is possible to easily improve thebonding strength between the first base member 21 and the second basemember 22 in the bonded body 1.

Second Embodiment

Next, description will be made on a second embodiment of the method ofmanufacturing the bonded body according to the present invention.

FIGS. 3A to 3E, 4F and 4G are sectional views for explaining the secondembodiment of the method of manufacturing the bonded body according tothe present invention. In this regard, it is to be noted that in thefollowing description, an upper side in each of FIGS. 3A to 3E, 4F and4G will be referred to as “upper” and a lower side thereof will bereferred to as “lower”.

Hereinafter, the second embodiment of the method of manufacturing thebonded body will be described by placing emphasis on the pointsdiffering from the first embodiment of the method of manufacturing thebonded body, with the same matters omitted from description.

The method according to this embodiment is the same as the methodaccording to the first embodiment, except that the bonding films 3 a and3 b are, respectively, formed on both the first base member 21 and thesecond base member 22, and the first base member 21 and the second basemember 22 are bonded together through the bonding films 3 a and 3 b tothereby obtain a bonded body 1.

Namely, the method according to this embodiment comprises: preparing afirst base member 21 having a first bonding film formation region 41 aand a second base member 22 having a second bonding film formationregion 41 b; imparting the liquid repellency for the liquid material 30to a region other than the first bonding film formation region 41 a ofthe first base member 21 and a region other than the second bonding filmformation region 41 b of the second base member 22, respectively, toform a first liquid repellent region 43 a and a second liquid repellentregion 43 b thereon; supplying the liquid material 30 onto the firstbase member 21 and the second base member 22, respectively, to formliquid coatings 31 a and 31 b on the respective bonding film formationregions 41 a and 41 b; drying the respective liquid coatings 31 a and 31b to obtain the respective bonding films 3 a and 3 b on the respectivebonding film formation regions 41 a and 41 b; applying energy to therespective bonding films 3 a and 3 b to develop a bonding property in avicinity of each of surfaces thereof; and laminating the first basemember 21 and the second base member 22 together so that the bondingfilm 3 a and the bonding film 3 b make close contact with each other tothereby obtain a bonded body 1 in which the base members 21 and 22 arepartially bonded together through the bonding films 3 a and 3 b.

Hereinafter, the method of manufacturing the bonded body according tothis embodiment will be described one after another.

[1] First, the first base member 21 and the second base member 22 areprepared in the same manner as in the first embodiment.

In this regard, in this embodiment, as shown in FIG. 3A, a region otherthan an outer circumference portion of one surface (the bonding surface23) of the first base member 21 is defined as the first bonding filmformation region 41 a on which the bonding film 3 a is to be formed,whereas a region other than an outer circumference portion of onesurface (the bonding surface 24) of the second base member 22 is definedas the second bonding film formation region 41 b on which the bondingfilm 3 b is to be formed.

[2] Next, as shown in FIG. 3B, the liquid repellency is imparted to (aliquid repellent film 431 a is formed on) a region (hereinafter,referred to as “first bonding film non-formation region 42 a”) otherthan the bonding film formation region 41 a of the bonding surface 23 ofthe first base member 21 to thereby form the first liquid repellentregion 43 a thereon.

Likewise, the liquid repellency is imparted to (a liquid repellent film431 b is formed on) a region (hereinafter, referred to as “secondbonding film non-formation region 42 b”) other than the bonding filmformation region 41 b of the bonding surface 24 of the second basemember 22 to thereby form the second liquid repellent region 43 bthereon.

In this regard, it is to be noted that a method of imparting the liquidrepellency to the first bonding film non-formation region 42 a of thefirst base member 21 may be the same as or different from a method ofimparting the liquid repellency is imparted to the second bonding filmnon-formation region 42 b of the second base member 22.

[3] Next, as shown in FIG. 3C, the liquid material 30 containing thesilicone material composed of the silicone compounds is supplied ontothe first bonding film formation region 41 a of the first base member 21to obtain the liquid coating 31 a. Likewise, the liquid material 30containing the silicone material composed of the silicone compounds issupplied onto the second bonding film formation region 41 b of thesecond base member 22 to obtain the liquid coating 31 b.

In this case, a composition, a polymerization degree of the siliconecompounds or the like of the silicone material contained in the liquidmaterial 30 to be supplied onto the first bonding film formation region41 a may be different from that of the silicone material contained inthe liquid material 30 to be supplied onto the second bonding filmformation region 41 b, but it is preferred that they are the same.

This makes it possible to improve affinity between the bonding film 3 aand the bonding film 3 b. As a result, through the steps which will bedescribed below, the bonding film 3 a and the bonding film 3 b can befirmly bonded together.

[4] Next, the liquid material 30 (the liquid coating 31 a) supplied ontothe first bonding film formation region 41 a of the first base member 21is dried. Likewise, the liquid material 30 (the liquid coating 31 b)supplied onto the second bonding film formation region 41 b of thesecond base member 22 is dried.

In this way, as shown in FIG. 3D, the bonding film 3 a patterned so asto correspond to a shape (a predetermined shape) of the first bondingfilm formation region 41 a is formed. Further, the bonding film 3 bpatterned so as to correspond to a shape (a predetermined shape) of thesecond bonding film formation region 41 b is formed.

[5] Next, as shown in FIG. 3E, the energy is applied to the bonding film3 a formed on the first base member 21. Likewise, the energy is appliedto the bonding film 3 b formed on the second base member 22.

When the energy is applied to the respective bonding films 3 a and 3 b,a part of molecular bonds of the silicone compounds present in thevicinity of each of the surfaces of the bonding films 3 a and 3 b arebroken. As a result, the surfaces are activated due to breakage of themolecular bonds. Namely, the bonding property is developed in thevicinity of each of the surfaces of the bonding films 3 a and 3 b.

[6] Next, the first base member 21 and the second base member 22 arelaminated together so that the bonding film 3 a and the bonding film 3 bmake close contact with each other (see FIG. 4F). At this time, sinceeach of the surfaces of the bonding films 3 a and 3 b has developed thebonding property in the step [5], the bonding film 3 a and the bondingfilm 3 b are chemically bonded together in a region where they (thefirst bonding film formation region 41 a and the second bonding filmformation region 41 b) overlap with each other to thereby obtain abonded body 1 shown in FIG. 4G.

Namely, in the bonded body 1, the first base member 21 and the secondbase member 22 are partially bonded together through the bonding film 3a formed on the first bonding film formation region 41 a and the bondingfilm 3 b formed on the second bonding film formation region 41 b.

After the bonded body 1 has been obtained, if necessary, at least onestep of the two steps [7A] and [7B] described above may be applied tothe bonded body 1. This makes it possible to further improve bondingstrength between the first base member 21 and the second base member 22(including bonding strength between the first base member 21 and thebonding film 3 a, bonding strength between the second base member andthe bonding film 3 b and bonding strength between the bonding films 3 aand 3 b) with ease.

According to this embodiment, the same operations and effects asdescribed in the first embodiment can be obtained.

Further, since the bonding films 3 a and 3 b are bonded together in thisembodiment, the two base members 21 and 22 can be more firmly bondedtogether compared with the first embodiment.

Although a pattern (a shape) of the bonding film 3 a formed on the firstbase member 21 is the same as that of the bonding film 3 b formed on thesecond base member 22 in this embodiment, the bonding films 3 a and 3 bmay have different patterns with each other.

Third Embodiment

Next, description will be made on a third embodiment of the method ofmanufacturing the bonded body according to the present invention.

FIGS. 5A and 5B are sectional views for explaining the third embodimentof the method of manufacturing the bonded body according to the presentinvention. In this regard, it is to be noted that in the followingdescription, an upper side in each of FIGS. 5A and 5B will be referredto as “upper” and a lower side thereof will be referred to as “lower”.

Hereinafter, the third embodiment of the method of manufacturing thebonded body will be described by placing emphasis on the pointsdiffering from the first and second embodiments of the method ofmanufacturing the bonded body, with the same matters omitted fromdescription.

The method according to this embodiment is the same as the methodaccording to the second embodiment, except that the first base member 21and the second base member 22 are laminated together through the bondingfilms 3 a and 3 b before the energy is applied thereto to obtain aprovisional bonded body 5, and then the energy is applied to theprovisional bonded body 5 to thereby obtain a bonded body 1.

Namely, the method according to this embodiment comprises: preparing thefirst base member 21 having the first bonding film formation region 41 aand the second base member 22 having the second bonding film formationregion 41 b; imparting the liquid repellency for the liquid material 30to the region other than the bonding film formation region 41 a of thefirst base member 21 and the region other than the bonding filmformation region 41 b of the second base member 22, respectively, toform the first liquid repellent region 43 a and the second liquidrepellent region 43 b thereon; supplying the liquid material 30 onto thefirst base member 21 and the second base member 22, respectively, toform liquid coatings 31 a and 31 b on the respective bonding filmformation regions 41 a and 41 b; drying the respective liquid coatings31 a and 31 b to obtain the respective bonding films 3 a and 3 b on therespective bonding film formation regions 41 a and 41 b; laminating thefirst base member 21 and the second base member 22 together so that thebonding film 3 a and the bonding film 3 b make close contact with eachother to obtain the provisional bonded body 5; and applying energy tothe respective bonding films 3 a and 3 b included in the provisionalbonded body 5 to thereby obtain a bonded body 1 in which the basemembers 21 and 22 are partially bonded together through the bondingfilms 3 a and 3 b.

Hereinafter, the method of manufacturing the bonded body according tothis embodiment will be described one after another.

[1] to [4] First, the bonding film 3 a is formed on the first basemember 21 and the bonding film 3 b is also formed on the second basemember 22 in the same manner as in the steps [1] to [4] described in thesecond embodiment.

[5] Next, as shown in FIG. 5A, the first base member 21 and the secondbase member 22 are laminated together so that the bonding film 3 a andthe bonding film 3 b make close contact with each other. In this way,the provisional bonded body 5 can be obtained. In this state, thebonding film 3 a and the bonding film 3 a are not bonded together in theprovisional bonded body 5.

Therefore, since the first base member 21 can be slid with respect tothe second base member 22, it is possible to finely adjust a relativeposition therebetween with ease. As a result, dimensional accuracy ofthe finally obtained bonded body 1 can be further improved.

[6] Next, the energy is applied to the bonding films 3 a and 3 bincluded in the provisional bonded body 5. Specifically, as shown inFIG. 5B, application of the energy to the bonding films 3 a and 3 b isperformed by irradiating an ultraviolet ray on the provisional bondedbody 5.

When the ultraviolet ray is irradiated on the bonding films 3 a and 3 bincluded in the provisional bonded body 5, a part of the molecular bondsof the silicone compounds present in the vicinity of each of thesurfaces of the bonding films 3 a and 3 b are broken. As a result, thesurfaces are activated due to breakage of the molecular bonds. Namely,the bonding property is developed in the vicinity of each of thesurfaces of the bonding films 3 a and 3 b.

Due to the bonding property, the bonding film 3 a and the bonding film 3b are chemically bonded together in the region where they (the firstbonding film formation region 41 a and the second bonding film formationregion 41 b) overlap with each other to thereby obtain a bonded body 1shown in FIG. 5B. Namely, in the bonded body 1, the first base member 21and the second base member 22 are partially bonded together through thebonding film 3 a formed on the first bonding film formation region 41 aand the bonding film 3 b formed on the second bonding film formationregion 41 b.

The application method of the energy is not limited to the method inwhich the ultraviolet ray is irradiated on the provisional bonded body5, but the same method as described in the first embodiment may be usedas the application method of the energy.

Hereinafter, description will be made on a method in which the bondingfilms 3 a and 3 b included in the provisional bonded body 5 are heatedand a method in which a compressing force is imparted to the bondingfilms 3 a and 3 b.

In the case where the bonding films 3 a and 3 b are heated, a heatingtemperature is preferably set to a range of about 25 to 100° C., and ismore preferably set to a range of about 50 to 100° C. By heating thebonding films 3 a and 3 b at the temperature within the above range, thebonding films 3 a and 3 b can be reliably activated while reliablypreventing thermal alteration and deterioration thereof.

Further, a heating time is set great enough to break the molecular bondsof the silicone compounds present in the vicinity of each of thesurfaces of the bonding films 3 a and 3 b. Specifically, the heatingtime may be preferably in the range of about 1 to 30 minutes if theheating temperature is set to the above mentioned range.

Furthermore, the bonding films 3 a and 3 b may be heated by any heatingmethod. Examples of the heating method include various kinds of methodssuch as a method of using a heater, a method of irradiating an infraredray and a method of making contact with a flame.

On the other hand, in the case where the energy is applied to thebonding films 3 a and 3 b by imparting the compressive force to thebonding films 3 a and 3 b, it is preferred that the provisional bondedbody 5 is compressed in a direction that the first base member 21 andthe second base member 22 come close to each other. Specifically, apressure in compressing the provisional bonded body 5 is preferably inthe range of about 0.2 to 10 MPa, and more preferably in the range ofabout 1 to 5 MPa.

This makes it possible to easily apply appropriate energy to the bondingfilms 3 a and 3 b by merely performing a compressing operation, whichensures that a sufficiently high bonding property is developed in eachof the bonding films 3 a and 3 b. Although the pressure may exceed theabove upper limit value, it is likely that damages and the like occur inthe first base member 21 and the second base member 22, depending on theconstituent materials thereof.

Further, a compressing time is not particularly limited to a specificvalue, but is preferably in the range of about 10 seconds to 30 minutes.In this regard, it is to be noted that the compressing time can besuitably changed, depending on magnitude of the compressive force.Specifically, the compressing time can be shortened as the compressiveforce becomes greater.

After the bonded body 1 has been obtained, if necessary, at least onestep of the two steps [7A] and [7B] described above may be applied tothe bonded body 1. This makes it possible to further improve the bondingstrength between the first base member 21 and the second base member 22(including the bonding strength between the first base member 21 and thebonding film 3 a, the bonding strength between the second base member 22and the bonding film 3 b and the bonding strength between the bondingfilms 3 a and 3 b) with ease.

According to this embodiment, the same operations and effects asdescribed in the first and second embodiments can be obtained.

The method of manufacturing the bonded body according to the presentinvention described above can be used in bonding different kinds ofmembers together.

Examples of an article (a bonded body) to be manufactured by such amethod of manufacturing the bonded body include: semiconductor devicessuch as a transistor, a diode and a memory; piezoelectric devices suchas a crystal oscillator; optical devices such as a reflecting mirror, anoptical lens, a diffraction grating and an optical filter; photoelectricconversion devices such as a solar cell; semiconductor substrates havingsemiconductor devices mounted thereon; insulating substrates havingwirings or electrodes formed thereon; ink-jet type recording heads;parts of micro electromechanical systems such as a micro reactor and amicro mirror; sensor parts such as a pressure sensor and an accelerationsensor; package parts of semiconductor devices or electronic components;recording media such as a magnetic recording medium, a magneto-opticalrecording medium and an optical recording medium; parts for displaydevices such as a liquid crystal display device, an organic EL deviceand an electrophoretic display device; parts for fuel cells; and thelike.

Liquid Droplet Ejection Head

Hereinafter, description will be made on an embodiment of a liquiddroplet ejection head in which the bonded body according to the presentinvention is used.

FIG. 6 is an exploded perspective view showing an ink jet type recordinghead (the liquid droplet ejection head) in which the bonded bodyaccording to the present invention is used. FIG. 7 is a section viewillustrating a main portion of the ink jet type recording head shown inFIG. 6. FIG. 8 is a schematic view showing one embodiment of an ink jetprinter equipped with the ink jet type recording head shown in FIG. 6.In FIG. 6, the ink jet type recording head is shown in an inverted stateas distinguished from a typical use state.

The ink jet type recording head 10 shown in FIG. 6 is mounted to the inkjet printer 9 shown in FIG. 8.

The ink jet printer 9 shown in FIG. 8 includes a printer body 92, a tray921 provided in an upper rear portion of the printer body 92 for holdingrecording paper sheets P, a paper discharging port 922 provided in alower front portion of the printer body 92 for discharging the recordingpaper sheets P therethrough, and an operation panel 97 provided on anupper surface of the printer body 92.

The operation panel 97 is formed from, e.g., a liquid crystal display,an organic EL display, an LED lamp or the like. The operation panel 97includes a display portion (not shown) for displaying an error messageand the like and an operation portion (not shown) formed from variouskinds of switches.

Within the printer body 92, there are provided a printing device (aprinting means) 94 having a reciprocating head unit 93, a paper sheetfeeding device (a paper sheet feeding means) 95 for feeding therecording paper sheets P into the printing device 94 one by one and acontrol unit (a control means) 96 for controlling the printing device 94and the paper sheet feeding device 95.

Under control of the control unit 96, the paper sheet feeding device 95feeds the recording paper sheets P one by one in an intermittent manner.The recording paper sheet P passes near a lower portion of the head unit93. At this time, the head unit 93 makes reciprocating movement in adirection generally perpendicular to a feeding direction of therecording paper sheet P, thereby printing the recording paper sheet P.

In other words, an ink jet type printing operation is performed, duringwhich time the reciprocating movement of the head unit 93 and theintermittent feeding of the recording paper sheets P act as primaryscanning and secondary scanning, respectively.

The printing device 94 includes a head unit 93, a carriage motor 941serving as a driving power source of the head unit 93 and areciprocating mechanism 942 rotated by the carriage motor 941 forreciprocating the head unit 93.

The head unit 93 includes an ink jet type recording head 10(hereinafter, simply referred to as “head 10”) having a plurality ofnozzle holes 111 formed in a lower portion thereof, an ink cartridge 931for supplying an ink to the head 10 and a carriage 932 carrying the head10 and the ink cartridge 931.

Full color printing becomes available by using, as the ink cartridge931, a cartridge of the type filled with ink of four colors, i.e.,yellow, cyan, magenta and black.

The reciprocating mechanism 942 includes a carriage guide shaft 943whose opposite ends are supported on a frame (not shown) and a timingbelt 944 extending parallel to the carriage guide shaft 943.

The carriage 932 is reciprocatingly supported by the carriage guideshaft 943 and fixedly secured to a portion of the timing belt 944.

If the timing belt 944 wound around a pulley is caused to run in forwardand reverse directions by operating the carriage motor 941, the headunit 93 makes reciprocating movement along the carriage guide shaft 943.During this reciprocating movement, an appropriate amount of the ink isejected from the head 10 to print the recording paper sheets P.

The paper sheet feeding device 95 includes a paper sheet feeding motor951 serving as a driving power source thereof and a pair of paper sheetfeeding rollers 952 rotated by means of the paper sheet feeding motor951.

The paper sheet feeding rollers 952 include a driven roller 952 a and adriving roller 952 b, both of which face toward each other in a verticaldirection, with a paper sheet feeding path (the recording paper sheet P)remained therebetween. The driving roller 952 b is connected to thepaper sheet feeding motor 951.

Thus, the paper sheet feeding rollers 952 are able to feed the pluralityof the recording paper sheets P, which are held in the tray 921, towardthe printing device 94 one by one. In place of the tray 921, it may bepossible to employ a construction that can removably hold a paper sheetfeeding cassette containing the recording paper sheets P.

The control unit 96 is designed to perform printing by controlling theprinting device 94 and the paper sheet feeding device 95 based onprinting data inputted from a host computer, e.g., a personal computeror a digital camera.

Although not shown in the drawings, the control unit 96 is mainlycomprised of a memory that stores a control program for controlling therespective parts and the like, a piezoelectric element driving circuitfor driving piezoelectric elements (vibration sources) 14 to control anink ejection timing, a driving circuit for driving the printing device94 (the carriage motor 941), a driving circuit for driving the papersheet feeding device 95 (the paper sheet feeding motor 951), acommunication circuit for receiving the printing data from the hostcomputer, and a CPU electrically connected to the memory and thecircuits for performing various kinds of control with respect to therespective parts.

Electrically connected to the CPU are a variety of sensors capable ofdetecting, e.g., a remaining amount of the ink in the ink cartridge 931and a position of the head unit 93.

The control unit 96 receives the printing data through the communicationcircuit and then stores them in the memory. The CPU processes theseprinting data and outputs driving signals to the respective drivingcircuits, based on the data thus processed and data inputted from thevariety of sensors. Responsive to these signals, the piezoelectricelements 14, the printing device 94 and the paper sheet feeding device95 come into operation, thereby printing the recording paper sheets P.

Hereinafter, the head 10 will be described in detail with reference toFIGS. 6 and 7.

The head 10 includes a head main body 17 and a base body 16 forreceiving the head main body 17. The head main body 17 includes a nozzleplate 11, an ink chamber base plate 12, a vibration plate 13 and aplurality of piezoelectric elements (vibration sources) 14 bonded to thevibration plate 13. The head 10 constitutes a piezo jet type head ofon-demand style.

The nozzle plate 11 is made of, e.g., a silicon-based material such asSiO₂, SiN or quartz glass, a metal-based material such as Al, Fe, Ni, Cuor alloy containing these metals, an oxide-based material such asalumina or ferric oxide, a carbon-based material such as carbon black orgraphite, and the like.

The plurality of the nozzle holes 111 for ejecting ink dropletstherethrough are formed in the nozzle plate 11. A pitch of the nozzleholes 111 is suitably set according to a degree of printing accuracy.

The ink chamber base plate 12 is fixed or secured to the nozzle plate11. In the ink chamber base plate 12, there are formed a plurality ofink chambers (cavities or pressure chambers) 121, a reservoir chamber123 for reserving the ink supplied from the ink cartridge 931 and aplurality of supply ports 124 through which the ink is supplied from thereservoir chamber 123 to the respective ink chambers 121. These chambers121, 123 and 124 are defined by the nozzle plate 11, side walls (barrierwalls) 122 and the below mentioned vibration plate 13.

The respective ink chambers 121 are formed into a reed shape (arectangular shape) and are arranged in a corresponding relationship withthe respective nozzle holes 111. Volume of each of the ink chambers 121can be changed in response to vibration of the vibration plate 13 asdescribed below. The ink is ejected from the ink chambers 121 by virtueof this volume change.

As a base material of which the ink chamber base plate 12 is made, it ispossible to use, e.g., a monocrystalline silicon substrate, variouskinds of glass substrates or various kinds of resin substrates. Sincethese substrates are all generally used in the art, use of thesesubstrates makes it possible to reduce a manufacturing cost of the head10.

The vibration plate 13 is bonded to an opposite side of the ink chamberbase plate 12 from the nozzle plate 11. The plurality of thepiezoelectric elements 14 are provided on an opposite side of thevibration plate 13 from the ink chamber base plate 12.

In a predetermined position of the vibration plate 13, a communicationhole 131 is formed through a thickness of the vibration plate 13. Theink can be supplied from the ink cartridge 931 to the reservoir chamber123 through the communication hole 131.

Each of the piezoelectric elements 14 includes an upper electrode 141, alower electrode 142 and a piezoelectric body layer 143 interposedbetween the upper electrode 141 and the lower electrode 142. Thepiezoelectric elements 14 are arranged in alignment with generallycentral portions of the respective ink chambers 121.

The piezoelectric elements 14 are electrically connected to thepiezoelectric element driving circuit and are designed to be operated(vibrated or deformed) in response to the signals supplied from thepiezoelectric element driving circuit.

The piezoelectric elements 14 act as vibration sources. The vibrationplate 13 is vibrated by operation of the piezoelectric elements 14 andhas a function of instantaneously increasing internal pressures of theink chambers 121.

The base body 16 is made of, e.g., various kinds of resin materials orvarious kinds of metallic materials. The nozzle plate 11 is fixed to andsupported by the base body 16. Specifically, in a state that the headmain body 17 is received in a recess portion 161 of the base body 16, anedge of the nozzle plate 11 is supported on a shoulder 162 of the basebody 16 extending along an outer circumference of the recess portion161.

When bonding the nozzle plate 11 and the ink chamber base plate 12, theink chamber base plate 12 and the vibration plate 13, and the nozzleplate 11 and the base body 16 as mentioned above, the method ofmanufacturing the bonded body according to the present invention is usedin at least one bonded portion thereof.

In other words, the bonded body of the present invention is used in atleast one of a bonded body in which the nozzle plate 11 and the inkchamber base plate 12 are bonded together, a bonded body in which theink chamber base plate 12 and the vibration plate 13 are bondedtogether, and a bonded body in which the nozzle plate 11 and the basebody 16 are bonded together.

Such a head 10 exhibits increased bonding strength and chemicalresistance in bonding interfaces (the bonded portion), which in turnleads to increased durability and liquid tightness against the inkreserved in the respective ink chambers 121. As a result, the head 10 isrendered highly reliable.

Furthermore, highly reliable bonding is available even at an extremelylow temperature. There is an advantage that a head with an increasedarea can be fabricated from members made of materials having differentlinear expansion coefficients.

With the head 10 set forth above, no deformation occurs in thepiezoelectric body layer 143, in the case where a predetermined ejectionsignal has not been inputted from the piezoelectric element drivingcircuit, that is, a voltage has not been applied between the upperelectrode 141 and the lower electrode 142 of each of the piezoelectricelements 14.

For this reason, no deformation occurs in the vibration plate 13 and nochange occurs in the volumes of the ink chambers 121. Therefore, the inkdroplets have not been ejected from the nozzle holes 111.

On the other hand, the piezoelectric body layer 143 is deformed, in thecase where the predetermined ejection signal is inputted from thepiezoelectric element driving circuit, that is, the voltage is appliedbetween the upper electrode 141 and the lower electrode 142 of each ofthe piezoelectric elements 14.

Thus, the vibration plate 13 is heavily deflected to change the volumesof the ink chambers 121. At this moment, pressures within the inkchambers 121 are instantaneously increased and the ink droplets areejected from the nozzle holes 111.

when one ink ejection operation has ended, the piezoelectric elementdriving circuit ceases to apply the voltage between the upper electrode141 and the lower electrode 142. Thus, the piezoelectric elements 14 arereturned substantially to their original shapes, thereby increasing thevolumes of the ink chambers 121.

At this time, a pressure acting from the ink cartridge 931 toward thenozzle holes 111 (a positive pressure) is imparted to the ink. Thisprevents an air from entering the ink chambers 121 through the nozzleholes 111, which ensures that the ink is supplied from the ink cartridge931 (the reservoir chamber 123) to the ink chambers 121 in a quantitycorresponding to the quantity of the ink ejected.

By sequentially inputting ejection signals from the piezoelectricelement driving circuit to the piezoelectric elements 14 lying in targetprinting positions, it is possible to print an arbitrary (desired)letter, figure or the like.

The head 10 may be provided with thermoelectric conversion elements inplace of the piezoelectric elements 14. In other words, the head 10 mayhave a configuration in which the ink is ejected using a thermalexpansion of a material caused by the thermoelectric conversion elements(which is sometimes called a bubble jet method wherein the term “bubblejet” is a registered trademark).

In the head 10 configured as above, a film 114 is formed on the nozzleplate 11 in an effort to impart liquid repellency thereto. By doing so,it is possible to reliably prevent the ink droplets from adhering toperipheries of the nozzle holes 111, which would otherwise occur whenthe ink droplets are ejected from the nozzle holes 111.

As a result, it becomes possible to make sure that the ink dropletsejected from the nozzle holes 111 are reliably landed (hit) on targetregions.

EXAMPLES

Next, description will be made on a number of concrete examples of thepresent invention.

1. Manufacture of Bonded body

Example 1

First, a monocrystalline silicon substrate having a length of 20 mm, awidth of 20 mm and an average thickness of 1 mm was prepared as a firstbase member. A quartz glass substrate having a length of 20 mm, a widthof 20 mm and an average thickness of 1 mm was prepared as a second basemember. Both the monocrystalline silicon substrate and the quartz glasssubstrate were subjected to a surface treatment using oxygen plasma.

In this way, liquid wettability was imparted to the entire of thesurface of each of the monocrystalline silicon substrate and the quartzglass substrate.

Next, a silane coupling agent having a functional group including afluoroalkyl group (“KY-130” produced by Shin-Etsu Silicones) wasdissolved in a solvent (“FR thinner” produced by Shin-Etsu Silicones) soas to become 0.1 mass % to obtain a treatment liquid.

Thereafter, the treatment liquid was supplied onto an inner region (abonding film formation region) of each of the monocrystalline siliconsubstrate and the quartz glass substrate using an ink jet method. Inthis regard, the inner region was a region other than a frame-shapedcircumference region thereof having a width of 3 mm.

Next, the treatment liquid supplied onto each of the monocrystallinesilicon substrate and the quartz glass substrate was heated and driedunder a condition of 100° C.×15 minutes. In this way, liquid repellencywas imparted to the bonding film non-formation region of each of themonocrystalline silicon substrate and the quartz glass substrate to forma liquid repellent region thereon.

Next, a liquid material having a viscosity of 18.0 mPa·s at 25° C.(“KR-251” produced by Shin-Etsu Chemical Co., Ltd.) was prepared. Inthis regard, the liquid material contained a silicone material composedof silicone compounds each having a polydimethylsiloxane chemicalstructure, and toluene and isobutanol as a solvent.

Then, the liquid material was supplied onto the monocrystalline siliconsubstrate and the quartz glass substrate using a roll coating method. Atthis time, the liquid material supplied onto each of the monocrystallinesilicon substrate and the quartz glass substrate was repelled due to theliquid repellency of the liquid repellent region (the bonding filmnon-formation region) so that it did not adhere thereto and selectivelyadhered to the frame-shaped circumference region (the bonding filmformation region) thereof.

Next, the liquid material supplied onto each of the monocrystallinesilicon substrate and the quartz glass substrate was dried at normaltemperature (25° C.) for 24 hours. In this way, the liquid material washardened to thereby obtain a bonding film on each of the monocrystallinesilicon substrate and the quartz glass substrate.

Then, an ultraviolet ray was irradiated on the bonding film formed oneach of the monocrystalline silicon substrate and the quartz glasssubstrate under the following conditions.

Ultraviolet Ray Irradiation Conditions

Composition of atmospheric gas: air atmosphere

Temperature of atmospheric gas: 20° C.

Pressure of atmospheric gas: atmospheric pressure (100 kPa)

Wavelength of ultraviolet ray: 172 nm

Irradiation time of ultraviolet ray: 5 minutes

Next, when one minute elapsed after the ultraviolet ray was irradiatedon the bonding films, the monocrystalline silicon substrate and thequartz glass substrate were laminated together so that the bonding filmsmade contact with each other to thereby obtain a bonded body.

Then, the bonded body was heated at a temperature of 80° C. whilecompressing the same under a pressure of 3 MPa and were maintained for15 minutes. In this way, bonding strength between the monocrystallinesilicon substrate and the quartz glass substrate was improved.

Example 2

In this Example 2, a bonded body was manufactured in the same manner asin the Example 1, except that the heating temperature in compressing andheating the bonded body obtained was changed from 80° C. to 25° C.

Examples 3 to 13

In each of these Examples 3 to 13, a bonded body was manufactured in thesame manner as in the Example 1, except that the constitute material ofthe first base member and the constitute material of the second basemember were changed to materials shown in Table 1.

Example 14

In this Example 14, a bonded body was manufactured in the same manner asin the Example 1, except that the liquid repellency was imparted to thebonding film non-formation region of each of the monocrystalline siliconsubstrate and the quartz glass substrate by performing a plasmatreatment using a C₂F₆ gas as a treatment gas.

Example 15

In this Example 15, a bonded body was manufactured in the same manner asin the Example 1, except that the liquid repellency was imparted to thebonding film non-formation region of each of the monocrystalline siliconsubstrate and the quartz glass substrate by forming a plasmapolymerization film using a C₂F₆ gas as a raw gas.

Example 16

In this Example 16, a bonded body was manufactured in the same manner asin the Example 1, except that the bonding film was only formed on themonocrystalline silicon substrate and the bonding film was not formed onthe quartz glass substrate.

Example 17

First, a bonding film was formed on a frame-shaped circumference regionof a monocrystalline silicon substrate having a width of 3 mm in thesame manner as in the Example 1. On the other hand, a bonding film wasformed on a frame-shaped circumference region of a quartz glasssubstrate having a width of 3 mm in the same manner as in the Example14.

Next, the monocrystalline silicon substrate and the quartz glasssubstrate were laminated together so that the bonding films made contactwith each other to thereby obtain a provisional bonded body.

Then, an ultraviolet ray was irradiated on the provisional bonded bodyunder the following conditions.

Ultraviolet Ray Irradiation Conditions

Composition of atmospheric gas: nitrogen atmosphere

Temperature of atmospheric gas: 20° C.

Pressure of atmospheric gas: atmospheric pressure (100 kPa)

Wavelength of ultraviolet ray: 172 nm

Irradiation time of ultraviolet ray: 5 minutes

In this way, the monocrystalline silicon substrate and the quartz glasssubstrate were bonded together through the bonding films to therebyobtain a bonded body.

Then, the bonded body was heated at a temperature of 80° C. whilecompressing the same under a pressure of 3 MPa and were maintained for15 minutes. In this way, bonding strength between the monocrystallinesilicon substrate and the quartz glass substrate was improved.

Comparative Examples 1 to 3

In each of these Comparative Examples 1 to 3, a bonded body wasmanufactured in the same manner as in the Example 1, except thatmaterials shown in Table 1 were used as the constitute material of thefirst base member and the constitute material of the second base member,and frame-shaped circumference regions of the base members each having awidth of 3 mm were bonded together using an epoxy-based adhesive.

Comparative Examples 4 to 6

In each of these Comparative Examples 4 to 6, a bonded body wasmanufactured in the same manner as in the Example 1, except thatmaterials shown in Table 1 were used as the constitute material of thefirst base member and the constitute material of the second base member,and frame-shaped circumference regions of the base members each having awidth of 3 mm were bonded together using an Ag paste.

Reference Examples 1 to 3

In each of these Reference Examples 1 to 3, a bonded body wasmanufactured in the same manner as in the Example 1, except thatmaterials shown in Table 1 were used as the constitute material of thefirst base member and the constitute material of the second base member,the bonding film was formed on the entire of each of the bondingsurfaces of the base members and the ultraviolet ray was irradiated onthe entire of each of the bonding films.

In this way, the first base member and the second base member wereentirely bonded together through the bonding films.

2. Evaluation of Bonded Body

2.1 Evaluation of Bonding Strength (Splitting Strength)

Bonding strength was measured for each of the bonded bodies obtained inthe Examples 1 to 17, the Comparative Examples 1 to 6 and the ReferenceExamples 1 to 3.

The measurement of the bonding strength was performed by trying removalof the first base member from the second base member. The bondingstrength (load) was defined by a value measured just before the firstbase member was peeled off from the second base member.

As a result, the bonding strength measured for each of the bonded bodiesobtained in the Examples 1 to 17 was lower than the bonding strengthmeasured for each of the bonded bodies obtained in the ReferenceExamples 1 to 3.

This means that the bonding strength (a degree of the load) between thefirst base member and the second base member could be changed betweenthe case that the bonding films was formed on a part of the bondingsurface and the case that the bonding film was formed on the entire ofthe bonding surface. Namely, it became apparent that the bondingstrength between the first base member and the second base member couldbe changed by controlling the size of the bonding film.

Further, the bonding strength measured for each of the bonded bodiesobtained in the Examples 1 to 17 was higher than the bonding strengthmeasured for each of the bonded bodies obtained in the ComparativeExamples 1 to 6.

2.2 Evaluation of Dimensional Accuracy

Dimensional accuracy in a thickness direction was measured for each ofthe bonded bodies obtained in the Examples 1 to 17, the ComparativeExamples 1 to 6 and the Reference Examples 1 to 3.

The evaluation of the dimensional accuracy was performed by measuring athickness of each corner portion of the bonded body having a squireshape, calculating a difference between a maximum value and a minimumvalue of the thicknesses measured, and evaluating the differenceaccording to criteria described below.

Evaluation Criteria for Dimensional Accuracy

A: less than 10 μm

B: 10 μm or more

2.3 Evaluation of Chemical Resistance

Each of the bonded bodies obtained in the Examples 1 to 17, theComparative Examples 1 to 6 and the Reference Examples 1 to 3 wasimmersed in an ink for an ink-jet printer (“HQ4” produced by Seiko EpsonCorporation), which was maintained at a temperature of 80° C., for threeweeks.

Thereafter, the first base member was removed from the second basemember, and it was checked whether or not the ink penetrated into abonding interface of the bonded body. The result of the check wasevaluated according to criteria described below.

Evaluation Criteria for Chemical Resistance

A: The ink did not penetrate into the bonded body at all.

B: The ink penetrated into the corner portions of the bonded bodyslightly.

C: The ink penetrated along the edge portions of the bonded body.

D: The ink penetrated into the inside of the bonded body.

2.4 Evaluation of Shape Change

Shape changes of the first base member and the second base member werechecked for each of the bonded bodies obtained in the Examples 1 to 17,the Comparative Examples 1 to 6 and the Reference Examples 1 to 3.

Specifically, warp amounts of the first base member and the second basemember were measured before and after the bonded body was manufactured,a change between the warp amounts was evaluated according to criteriadescribed below.

Evaluation Criteria for Change between Warp Amounts

A: The warp amounts of the first base member and the second base memberwere changed hardly before and after the bonded body was manufactured.

B: The warp amounts of the first base member and the second base memberwere changed slightly before and after the bonded body was manufactured.

C: The warp amounts of the first base member and the second base memberwere changed rather significantly before and after the bonded body wasmanufactured.

D: The warp amounts of the first base member and the second base memberwere changed significantly before and after the bonded body wasmanufactured.

TABLE 1 Conditions for Manufacturing Bonded Body Evaluation ResultsConstituent Constituent Method of Irradiation Heating Change Material ofMaterial of Imparting of Temperature of First Base Second Base LiquidBonding Bonding Ultraviolet of Bonded Dimensional Chemical Warp MemberMember Repellency Film Region Ray Body Accuracy Resistance Amounts Ex. 1Silicon Quartz Glass Silane Silicon a Part Before 80° C. A A A CouplingAgent Material of Laminating Ex. 2 Silicon Quartz Glass Silane SiliconBonding 25° C. A A A Coupling Agent Material Surface Ex. 3 SiliconSilicon Silane Silicon 80° C. A A A Coupling Agent Material Ex. 4Silicon Stainless Silane Silicon 80° C. A A B Steel Coupling AgentMaterial Ex. 5 Silicon Aluminum Silane Silicon 80° C. A A B CouplingAgent Material Ex. 6 Silicon PET Silane Silicon 80° C. A A B CouplingAgent Material Ex. 7 Silicon PI Silane Silicon 80° C. A A B CouplingAgent Material Ex. 8 Quartz Glass Quartz Glass Silane Silicon 80° C. A AA Coupling Agent Material Ex. 9 Quartz Glass Stainless Silane Silicon80° C. A A B Steel Coupling Agent Material Ex. 10 Stainless PET SilaneSilicon 80° C. A A B Steel Coupling Agent Material Ex. 11 Stainless PISilane Silicon 80° C. A A B Steel Coupling Agent Material Ex. 12Stainless Aluminum Silane Silicon 80° C. A A A Steel Coupling AgentMaterial Ex. 13 Stainless Stainless Silane Silicon 80° C. A A A SteelSteel Coupling Agent Material Ex. 14 Silicon Quartz Glass Plasma Silicon80° C. A A A Treatment Material Ex. 15 Silicon Quartz Glass PlasmaSilicon 80° C. A A A Polymerization Material Film Ex. 16 Silicon QuartzGlass Silane Silicon 80° C. A A B Coupling Agent Material (Only Silicon(Only Substrate) Silicon Substrate) Ex. 17 Silicon Quartz Glass SilaneSilicon After 80° C. A A A Coupling Agent Material Laminating Comp.Silicon Quartz Glass — Epoxy-based a Part — 80° C. B C A Ex. 1 Adhesiveof Comp. Silicon Silicon Bonding 80° C. B C A Ex. 2 Surface Comp.Silicon Stainless 80° C. B C B Ex. 3 Steel Comp. Stainless Quartz GlassConductive 80° C. B C B Ex. 4 Steel Paste Comp. Stainless Silicon (AgPaste) 80° C. B C B Ex. 5 Steel Comp. Stainless Stainless 80° C. B C AEx. 6 Steel Steel Ref. Silicon Quartz Glass — Silicon Entire — 80° C. AA C Ex. 1 Material of Ref. Silicon Silicon Silicon Bonding 80° C. A A CEx. 2 Material Surface Ref. Silicon Stainless Silicon 80° C. A A C Ex. 3Steel Material *PET: Polyethylene Terephthalate, PI: Polyimide

As is apparent in Table 1, the bonded bodies obtained in the Examples 1to 17 exhibited excellent characteristics in all the items of thedimensional accuracy, the chemical resistance and the changes of thewarp amounts. Further, the bonded bodies obtained in the Examples 1 to17 had the changes of the warp amounts smaller than those of the bondedbodies obtained in the Reference Examples 1 to 3.

On the other hand, the bonded bodies obtained in the ComparativeExamples 1 to 6 did not have enough chemical resistance. Further, it wasconfirmed that the dimensional accuracy of the bonded bodies was low.

1. A method of manufacturing a part of a micro electromechanical system,the part including a bonded body in which a first base member and asecond base member are bonded together through a bonding film formedusing a liquid material containing a silicone material composed ofsilicone compounds, the method comprising: preparing the first basemember having a surface, a bonding film formation region, where thebonding film is to be formed, provided on the surface and a bonding filmnon-formation region, where the bonding film is not to be formed,provided on the surface so as to be adjacent to the bonding filmformation region, and the second base member; imparting liquidrepellency for the liquid material to at least a part of the bondingfilm non-formation region to form a liquid repellent region thereon;supplying the liquid material onto the first base member to selectivelyform a liquid coating on the bonding film formation region with the aidof the liquid repellency of the liquid repellent region; drying theliquid coating to obtain the bonding film on the bonding film formationregion; and bonding the first base member and the second base membertogether through the bonding film due to a bonding property developed ina vicinity of a surface of the bonding film by applying energy theretoto thereby obtain the bonded body.
 2. The method as claimed in claim 1,wherein each of the silicone compounds has a polydimethylsiloxanechemical structure as a main chemical structure thereof.
 3. The methodas claimed in claim 1, wherein each of the silicone compounds has atleast one silanol group.
 4. The method as claimed in claim 1, whereinthe liquid repellent region is formed so as to surround the bonding filmformation region.
 5. The method as claimed in claim 1, wherein theliquid repellent region is formed by introducing liquid repellentfunctional groups each having the liquid repellency for the liquidmaterial to the bonding film non-formation region or by forming a liquidrepellent film having the liquid repellency for the liquid material onthe bonding film non-formation region.
 6. The method as claimed in claim5, wherein each of the liquid repellent functional groups is afluoroalkyl group.
 7. The method as claimed in claim 5, wherein theliquid repellent film is a self-assembled film or a plasmapolymerization film.
 8. The method as claimed in claim 1, wherein in theliquid material supplying step, before the liquid material is suppliedonto the first base member, the bonding film formation region issubjected to a liquid wettable treatment capable of imparting liquidwettability for the liquid material to the bonding film formationregion.
 9. The method as claimed in claim 8, wherein the liquid wettabletreatment is performed by introducing hydroxyl groups to the bondingfilm formation region.
 10. The method as claimed in claim 1, wherein inthe step of bonding the first base member and the second base member,after the first base member and the second base member are laminatedtogether through the bonding film, the energy is applied to the bondingfilm to thereby bond them together through the bonding film.
 11. Themethod as claimed in claim 1, wherein in the bonding step, the energy isapplied to the bonding film by at least one method selected from thegroup consisting of a method in which an energy beam is irradiated onthe bonding film, a method in which the bonding film is heated and amethod in which a compressive force is applied to the bonding film. 12.The method as claimed in claim 11, wherein the energy beam is anultraviolet ray having a wavelength of 126 to 300 nm.
 13. The method asclaimed in claim 11, wherein a temperature of the heating is in therange of 25 to 100° C.
 14. The method as claimed in claim 11, whereinthe compressive force is in the range of 0.2 to 10 MPa.
 15. The methodas claimed in claim 14, wherein in the bonding step, the energy isapplied to the bonding film in an air atmosphere.
 16. The method asclaimed in claim 1, wherein an average thickness of the bonding film isin the range of 100 nm to 100 μm.
 17. The method as claimed in claim 1,wherein at least a portion of the first base member which makes contactwith the bonding film is composed of a silicon material, a metalmaterial or a glass material as a major component thereof.
 18. Themethod as claimed in claim 1, wherein the second base member has abonding film which is the same as the bonding film formed on the firstbase member, and wherein in the bonding step, the first base member andthe second base member are bonded together through the bonding films.19. The method as claimed in claim 1, further comprising subjecting thebonded body to a treatment for improving bonding strength between thefirst base member and the second base member after the bonding step. 20.The method as claimed in claim 19, wherein the treatment for improvingthe bonding strength is performed by at least one method selected fromthe group consisting of a method in which an energy beam is irradiatedon the bonding film and a method in which the bonding film is heated.21. A part of micro electromechanical system manufactured by using themethod defined by claim 1.